Avoidable Medical Errors: Causes, Consequences, & Solutions

Most avoidable medical errors are not caused by one careless person. They happen where information gets handed from one place to another and something falls out along the way. The sections below show where those gaps sit and what you can do at the bedside, at the pharmacy counter and at home.

Medical errors refer to preventable mistakes in healthcare that can cause harm to patients. These errors can occur in diagnosis, treatment, medication administration, surgery, or even during routine medical procedures. Published estimates of how often preventable harm happens in hospitals, and how many deaths it contributes to, differ a great deal between studies and are still debated, so no single number should be treated as settled.

What is not debated is that preventable harm is common enough that patient safety is a central focus for hospitals and regulators. The following are some of the common errors and evidence-based strategies to reduce medication errors, including prescribing correct psychiatric drugs and dosages.

Overview of Avoidable Medical Errors

While some medical errors are complex and difficult to prevent, many are avoidable with improved processes and safety measures. Some of the most common avoidable medical errors include:

• Medication errors – Incorrect dosages, wrong medications, or improper administration routes.
• Misdiagnosis – Failure to correctly diagnose a condition, leading to delayed or incorrect treatment.
• Surgical errors – The surgical errors include active and latent errors. Active error relates to operating on the wrong site, leaving surgical instruments inside the patient, or complications due to poor technique. While latent errors are the ones that arise due to the problems within the system, doctors or healthcare specialists who double-check the system before initiating the surgery may avoid such errors and that is known as a ‘near-miss’.
• Hospital-acquired infections – Infections caused by inadequate hygiene or sterilization protocols.
• Communication failures – Lack of clear instructions between healthcare professionals, leading to errors in patient care.

Medical Errors in Depth

Medical errors can have severe consequences, ranging from minor discomfort to life-threatening complications. Below are some of the most dangerous medical errors that can lead to serious adverse effects, including death:

1. Medication Errors

Medication errors are one of the most common and dangerous types of medical mistakes. These include:

• Prescribing the wrong drug – A doctor may prescribe a medication that interacts poorly with other drugs or does not suit the patient’s condition.
• Incorrect dosage – A small variation in drug dosage can have life-threatening consequences.
• Failure to consider patient genetics – Some patients metabolize medications differently due to genetic variations, making certain drugs ineffective or toxic.

2. Misdiagnosis and Delayed Diagnosis

Misdiagnosing or delaying the correct diagnosis can lead to incorrect treatments, worsening the patient’s condition. Some conditions commonly misdiagnosed include:

• Heart attacks – Sometimes mistaken for acid reflux or anxiety.
• Stroke – Often misdiagnosed as migraines or vertigo, delaying critical treatment.
• Infections – Sepsis (a severe infection in the bloodstream) can be misdiagnosed, leading to delayed treatment and fatal consequences.

3. Surgical Errors

Errors in surgery can cause life-threatening complications. These mistakes can be classified into active errors (errors caused by direct human action) and latent errors (system failures or hidden conditions that contribute to errors).

Active Errors in Surgery

• Wrong-site surgery – A surgeon operating on the wrong limb or organ due to miscommunication or incorrect charting.
• Anesthesia misadministration – Giving too much or too little anesthesia, causing respiratory distress, brain damage, or even death.
• Accidental organ or nerve damage – A slip of the scalpel leading to unintended injury during surgery.

Latent Errors in Surgery

• Inadequate pre-surgical protocols – Poorly designed checklists or rushed preoperative verification can lead to wrong-site surgeries or incorrect procedures.
• Defective equipment or improper sterilization – If a faulty surgical instrument is used due to a lack of routine maintenance, it may cause infections or internal injuries.
• Communication breakdown among medical staff – When nurses, anesthesiologists, or surgeons receive incomplete or incorrect patient information, the risk of surgical complications increases.
• Poor organizational policies – Inconsistent staff training, lack of double-check systems, or fatigue due to long working hours can create conditions that make errors more likely to occur.

4. Healthcare-Associated Infections (HAIs)

Hospital-acquired infections occur due to poor hygiene practices. Common HAIs include:

• Methicillin-resistant Staphylococcus aureus (MRSA) – A dangerous antibiotic-resistant infection.
• Clostridioides difficile (C. diff) – A severe infection affecting the intestines, often caused by overuse of antibiotics.
• Urinary tract infections (UTIs) – Frequently caused by prolonged catheter use.

Examples of Medical Errors

The kinds of cases described in patient safety reviews show how much is at stake. Typical examples include:

• Incorrect medication administration – A patient receiving a chemotherapy dose far higher than intended, because the order was misread and no second check caught it.
• Wrong-patient surgery – A patient taken to the operating room for a procedure meant for someone else after records were mixed up.
• Delayed stroke diagnosis – A younger patient with stroke symptoms sent home with migraine treatment, so the window for clot-busting treatment closed.

Medication Errors Due to High or Low Doses

While higher doses can lead to adverse drug reactions, low doses (unnecessarily) on top of slow or delayed treatment can lead to drug resistance.

High Medication Doses

Excessive medication doses can lead to overdose, toxicity, or death. If you suspect an overdose or a severe reaction, call 911 (or your local emergency number) right away. In the United States, Poison Control is available at 1-800-222-1222, and the 988 Suicide and Crisis Lifeline is available if an overdose may have been intentional. Some drugs with narrow safety margins include:

• Opioids (e.g., Morphine, Fentanyl, Oxycodone) – High doses can cause respiratory depression, leading to death.
• Warfarin (blood thinner) – Overdosing can cause severe internal bleeding.
• Insulin (for diabetes) – Too much insulin can lead to dangerously low blood sugar levels (hypoglycemia), causing coma or death.

Low Medication Doses

Unless required, low-dose medications can result in drug resistance. Inadequate drug levels may:

• Fail to treat – Lower than required dosage can prolong the disease, hence worsening the illness.
• Create drug-resistant bacteria or viruses – This is especially dangerous in antibiotics, as bacteria adapt and become harder to treat (e.g., antibiotic-resistant tuberculosis).
• Reduce the effectiveness of cancer treatments – Insufficient chemotherapy doses can allow cancer cells to survive and become resistant to future treatments.

How Pharmacogenomic (PGx) Testing Helps Prevent Medical Errors

Pharmacogenomics testing, also known as PGx testing gives insights into your genetic makeup, thus, helping to determine how you metabolize (process) medications. This helps doctors prevent medical errors by ensuring:

• Personalized medication plans – Doctors can prescribe the right drug at the correct dose based on a patient’s genetic profile.
• Reduced risk of side effects – Identifying genetic variations that may cause adverse drug reactions.
• Prevention of treatment failures – Ensuring that prescribed drugs are effective for the patient.

For example, codeine is a prodrug that the liver enzyme CYP2D6 has to convert into morphine. Poor metabolizers form very little morphine and get little pain relief, while ultrarapid metabolizers form too much and face a higher risk of dangerous sedation and breathing problems. PGx results help a prescriber pick an alternative painkiller in either case.

How does a simple at-home PGx test work?

Does the FDA recognise Pharmacogenomics?

According to the FDA, “Pharmacogenomics can play an important role in identifying responders and non-responders to medications, avoiding adverse events, and optimizing drug dose.” Drugs that should specifically be genotype-based may contain the following labels:

• Risk for adverse events
• Trial design features
• Mechanisms of drug action
• Genotype-specific dosing
• Drug exposure and clinical response variability
• Polymorphic drug target and disposition genes

Here we have some of the medications in the U.S. that the FDA has labelled as they may cause adverse reactions or affect individuals differently, thus, genotype-based administration is recommended:

Amoxapine (Psychiatry): A tricyclic antidepressant drug metabolized by CYP2D6 enzyme, states on its boxed overdosage section that although the occurrence is less than 5% only, overdose may develop renal failure two to five days after toxic overdosage in patients who may appear otherwise recovered. Moreover, acute tubular necrosis with rhabdomyolysis and myoglobinuria is the most common renal complication in cases of overdose.

Citalopram (Psychiatry): Available under the brand name Celexa, Citalopram is an SSRI (selective serotonin reuptake inhibitor) drug metabolized by the CYP2C19 enzyme. states under its dosage and administration section that due to the risk of QT prolongation Celexa 20 mg per/day dose is the maximum recommended in CYP2C19 poor metabolizers.

Escitalopram (Psychiatry): Available under the brand name Lexapro, Escitalopram is an SSRI drug metabolized by the CYP2C19 enzyme, states under its adverse reaction sections that commonly observed adverse reactions include ejaculation disorder (primarily ejaculatory delay), increased sweating, nausea, decreased libido, and fatigue etc.

What Is Pharmacogenomics (PGx) Testing?

Pharmacogenomics (PGx) is the study of how genes affect a person’s response to drugs. A PGx test analyses DNA to determine how an individual’s body will metabolize specific medications. This information helps doctors:

• Avoid prescribing drugs that may be ineffective or harmful.
• Adjust medication dosages for safer treatment.
• Reduce trial-and-error in prescribing medications.

RPh Labs offers at-home PGx testing that uses a simple cheek (buccal) swab, not a blood draw or a saliva sample. The 20-gene panel reports on 240+ medications, and a PharmD pharmacist reviews every report, so your doctor has clearer information when building a safer treatment plan for you.

Where avoidable medical errors cluster: the handoff points

Avoidable medical errors are not spread evenly across a hospital stay or a course of treatment. They concentrate at the moments when responsibility moves, because that is when the record and the reality drift apart.

• Admission: the home medicine list is rebuilt from memory, and something gets dropped, duplicated or written at the wrong strength.
• Shift change and transfer: the pending test, the allergy, the plan for tomorrow morning all depend on the handover being complete.
• Discharge: new drugs start, old ones should stop, and nobody is quite sure which list the patient goes home with.
• Between clinicians: a specialist starts a drug the primary care team never hears about.
• Results that never close the loop: a test comes back abnormal and no one owns the follow up.

The fixes that work are unglamorous. Structured handover formats, medication reconciliation at every transition, barcode scanning at the bedside, computerized order entry with interaction alerts, and read-back of verbal orders all reduce avoidable medical errors measurably.

As a patient or family member you can plug one gap yourself: carry one current medicine list and hand it over at every transition. You are the only person present at every single handoff, which makes you the most reliable link in the chain.

How to prevent medication errors at home

Home is where most doses are actually taken, and it gets the least attention in discussions of avoidable medical errors. These habits are the core of how to prevent medication errors without any special equipment.

1. Use one pharmacy so interaction checks run against your whole list.
2. Read the label at pickup and compare it to what you were told. Wrong strength and wrong directions are easier to catch in the parking lot than three weeks later.
3. Watch for look-alike and sound-alike names. Hydroxyzine and hydralazine, or clonidine and clonazepam, are different drugs entirely.
4. Keep one written list with drug, strength, dose, timing and purpose, and update it the day anything changes.
5. Use a weekly organizer if you take several medicines, and fill it at the same time each week rather than in a hurry.
6. Ask before splitting or crushing anything, since extended release products often must be swallowed whole.
7. Store medicines out of reach of children and away from heat and damp, and dispose of expired ones properly.

One more habit is worth building into how to prevent medication errors: repeat the instructions back to the prescriber or pharmacist in your own words. That teach-back step catches misunderstandings that a nod does not.

If a dose is missed, ask what to do rather than guessing. Doubling up is unsafe with some drugs and pointless with others, and the answer differs by medicine.

For a suspected overdose, call 911 in the United States for anything severe, and Poison Control at 1-800-222-1222 for guidance. Never try to correct a suspected overdose at home on your own.

Medication errors in hospitals: what a patient or family member can do

You cannot audit a pharmacy from a hospital bed to rule out medication errors in hospitals, but you can close a few of the gaps where medication errors in hospitals usually begin. Ask a family member or friend to help if you are unwell, because advocacy is hard work when you feel awful.

• Bring the actual bottles, or a photo of each label, rather than a list from memory.
• Ask what each new medicine is for, and say something if a pill looks different from what you expected.
• Expect your wristband to be checked before every dose, and speak up if it is not.
• Ask which of your home medicines are being continued, which are paused, and why.
• Ask about allergies being on the chart in the way you described them.
• At discharge, ask for a single printed list that says what to take, what to stop and what changed.

The discharge list is the highest value document of the whole stay and the place where medication errors in hospitals most often become errors at home. Most preventable readmissions involving medicines trace back to a discharge list that did not match what the patient actually had at home.

If something feels wrong, say so immediately and ask for a pause. Every hospital has a patient advocate or ombudsman, and asking for one is a normal request rather than a complaint. Reducing medication errors in hospitals depends on people speaking up early, not on being polite.

Diagnostic errors: the ones patients notice first

Diagnostic errors are harder to see than a wrong pill because the harm arrives as time passing rather than as an obvious event. Three questions cover most of the ground for spotting diagnostic errors early.

1. What else could this be, and what would we expect to see if it were that?
2. What should make me come back sooner, or go to an emergency department?
3. Who is responsible for following up on this test, and how will I get the result?

That third question matters most. A result that nobody chases is one of the commonest diagnostic errors, and the safest assumption is that no news is not good news. Ask for results in writing, through the patient portal if you have one.

Keep a short timeline of symptoms: when they began, what makes them better or worse, what has changed. Clinicians reason from patterns, and a written timeline gives them a better pattern than a recollection under pressure does.

Second opinions are a reasonable defense against diagnostic errors, not a rudeness, particularly for a serious diagnosis or a treatment with lasting consequences. Bring your records so the second clinician is not starting from scratch.

Some presentations carry a higher risk of being missed. Chest discomfort blamed on indigestion, stroke symptoms blamed on migraine, and early sepsis blamed on a virus are the classic examples, and all three are emergencies when they are real.

A patient safety checklist you can actually use

Print this patient safety checklist, or keep it in your phone notes. A patient safety checklist only helps if it is short enough to use on a bad day.

1. One current medicine list, including over the counter products and supplements, updated the day it changes.
2. Allergies and past reactions written as what happened, not just the word allergy.
3. One pharmacy for everything.
4. The name of the clinician coordinating your care, and how to reach them.
5. Your latest kidney function result if you take drugs that depend on it.
6. Any gene test results that affect prescribing, kept with your records.
7. A person who can advocate for you, and who knows where these documents are.

A patient safety checklist should extend to procedures too. Before any procedure, confirm your name, the procedure and the site with the team, and expect them to confirm it back. That pause is a standard part of surgical safety, and joining in is welcome rather than obstructive.

Running through a patient safety checklist before each appointment turns a rushed visit into a useful one, and it surfaces the mismatches that lead to avoidable medical errors long before they cause harm.

Where gene results prevent avoidable medical errors

Pharmacogenomic testing addresses one specific category: the case where the right drug, at an ordinary dose, is wrong for this particular person. It does nothing for wrong-site surgery, a lost result or any of the other avoidable medical errors above, and we would rather be clear about that boundary.

Within that category the evidence is solid, and the examples are concrete.

• Clopidogrel needs CYP2C19 to be activated, so a poor metabolizer gets less antiplatelet effect. The FDA label carries a boxed warning about it.
• Codeine and tramadol need CYP2D6 to become active, so a poor metabolizer may get little relief and an ultrarapid metabolizer can reach unexpectedly high levels.
• TPMT and NUDT15 variants raise the risk of severe blood count suppression from azathioprine and mercaptopurine.
• DPYD variants raise the risk of severe toxicity from fluorouracil and capecitabine.
• SLCO1B1 decreased function raises the risk of muscle problems with simvastatin.
• CYP2C9, VKORC1 and CYP4F2 all influence warfarin dose requirements.

The CPIC guidelines and the FDA table of pharmacogenomic biomarkers in drug labeling are the sources to check rather than a marketing page, including ours.

The RPh Labs at-home pharmacogenetic testing kit is a cheek swab, not a blood draw or a spit tube. It covers 20 genes, reports against more than 240 medications, and every report is reviewed by a PharmD pharmacist with a free consultation included. Our guide to which medications need a PGx test first is the honest place to start, because for many drugs the answer is that testing changes nothing.

Results are inherited, so they do not change over your lifetime. Filing them with your medical records is part of the same patient safety checklist as your allergy list.

After something goes wrong: what to ask and document

If you think one of these avoidable medical errors has occurred, the first priority is your current safety, and the second is a clear record. Both are easier if you act while the details are fresh.

1. Ask directly what happened, in plain language, and write down the answer with the date and who said it.
2. Ask what is being done now and what to watch for over the next days and weeks.
3. Request copies of your records, including medication administration records for a hospital stay.
4. Ask how to file a concern through the hospital’s patient safety or advocacy office.
5. Make sure the event is recorded on your chart so it informs future care.
6. Ask which clinician now owns the follow up, and when it happens.

Do not stop a medicine abruptly while you sort this out. Benzodiazepines, several antidepressants, antiseizure drugs, beta blockers and steroids can cause harm when discontinued suddenly, so any change belongs to a prescriber.

Reporting is not only about accountability, and it feeds directly into how to prevent medication errors for the next patient. Hospitals and regulators find patterns from individual reports, and how to prevent medication errors at scale is learned mostly from events that somebody bothered to write down.

Conclusion

Despite the advancement in the healthcare sector, avoidable medical errors are still causing adverse reactions and even deaths in some cases. Some of the evidence-based strategies to reduce medication errors, including latent and active medical errors, include following checklists, counting instruments, consulting your fellow doctors, nurses, or seniors.

Antithrombotic prophylaxis, and using radio-frequency identification to identify surgical sponges, consulting fellow doctors from the same specialty (in possible cases obviously), and prescribing genome-based drugs and dosages where necessary, such as psychiatry medications which tend to affect people differently based on specific enzyme functions. The FDA itself has labelled some drugs with specific terms indicating the need for genome-based dosage and precautions.

References NCBI.nih.Gov

Avoidable medical errors FAQ

What is the single best step in how to prevent medication errors?

Keep one accurate, current medicine list and use one pharmacy. Almost every interaction check, reconciliation step and safety alert in the system depends on a complete list. Include over the counter products and supplements, note the strength and the reason for each drug, and update it the day anything changes rather than before the next appointment.

How do I reduce the risk of medication errors in hospitals?

Bring your bottles or photos of the labels, ask what each new medicine is for, expect your wristband to be checked before every dose, and ask which home medicines are paused. At discharge, insist on one printed list showing what to take, what to stop and what changed. Ask for a patient advocate if something feels wrong.

Are diagnostic errors more common than surgical mistakes?

They are harder to count because the harm shows up as delay rather than as a single event, and many are never recorded. What is clear is that missed and delayed diagnoses are a major category of harm, especially for heart attack, stroke and sepsis. Asking what else this could be, and who is following up the test, helps.

What should be on a patient safety checklist for an older relative?

One current medicine list, allergies described as what actually happened, one pharmacy, the coordinating clinician’s name, the most recent kidney function result, any gene test results, and a named advocate who knows where those documents are. Add an annual review appointment where every bottle is brought in and someone asks what could safely come off.

Can pharmacogenomic testing prevent avoidable medical errors?

It prevents one category: the case where a standard dose of a reasonable drug is wrong for that person’s genetics. Clopidogrel, codeine, thiopurines, fluorouracil, warfarin and simvastatin are the clearest examples. It does not touch handoff failures, wrong-site surgery or lost results, and it does not replace monitoring such as INR or blood counts.

Who do I call if I think a medicine has caused harm?

Call 911 for breathing trouble, facial swelling, a blistering rash, uncontrolled bleeding or collapse. Otherwise call the prescriber and your pharmacy the same day, and Poison Control at 1-800-222-1222 for suspected overdose guidance. Do not stop the medicine on your own first, because several common drugs are dangerous to discontinue abruptly.