The three most common diseases that are often misdiagnosed  are colorectal cancer, lung cancer, and breast cancer. You can round up to the five most frequently misdiagnosed diseases by adding heart attack and prostate cancer to this list.

This article is based on a few academic articles involving over 1000 cases of patient safety incident reports, malpractice claims, morbidity and mortality rounds (conferences that review patient deaths and complications), and focus group responses where the researchers were able to find as many as 836 medical errors. Using all the data they’d collected and considering all the different aspects and possibilities of medical errors, the researchers identified several conditions that are most common in medical errors and missed diagnostics. Here we’ll discuss 6 of the most common diseases and conditions from that list:

  • Lung Cancer
  • Breast Cancer
  • Colorectal Cancer
  • Stroke
  • Lyme disease
  • MS or Multiple Sclerosis

What is the reason behind medical errors?

There are many reasons that medical errors and diagnostic errors happen. Some conditions are still not completely understood, so doctors aren’t aware of certain symptoms. Further, many conditions can cause similar symptoms which can lead to medical errors. The patient may fail to provide their doctor with the right information regarding their condition and its symptoms, or the doctor may order an incorrect test or read the test results incorrectly. All of the above and so many other things can be the reason behind medical errors.


While these conditions are all very complex, here we’re sharing some basic information to help familiarize you with the conditions more prone to be involved in medical errors.

Lung cancer

Lung cancer is the leading cause of death by cancer across the world. The lungs are two sponge-like organs within our chest. Lungs are responsible for taking in oxygen as we inhale and releasing carbon dioxide when we exhale, and then oxygenating blood as it circulates through the body.

lung cancer

Smoking significantly increases the risk of developing lung cancer, but this disease may occur in people who are not smokers themselves nor live with smokers. The longer that a person has been smoking equates to a higher risk of developing lung cancer. Quitting smoking will significantly lower your risk of developing not only lung cancer, but other cancers and some other conditions.

Colorectal cancer

In colorectal cancer, the development of cancerous cells starts with the cells that line either the rectum or the colon. The risk of medical errors and further damage is higher in this type of cancer because symptoms don’t typically appear until the condition has advanced further. It’s important to have regular checkups and provide detailed information about any symptoms to your doctor.

Colorectal Cancer

Breast cancer

Just like other cancer types, this cancer with a high risk of diagnostic error occurs when cells in the breast area start to grow abnormally. The first and most noticeable sign is feeling a lump in your chest if you have this kind of cancer. The lump is also called a tumor. You may also feel a sudden change in the size of your breast or notice changes in the area that surrounds it. Mammograms can be helpful with early detection of this disease.

Breast cancer


A stroke is a time-sensitive condition that requires immediate medical attention to prevent severe damage. Medical errors are common in stroke patients: in about 2 to 26 percent of all stroke patients, their condition is underdiagnosed, and over-diagnosed in 30 to 43 percent of patients. The signs and symptoms of stroke may seem like those of other conditions such as migraines, epileptic seizures, psychogenic disease, demyelinating disease, etc.


Lyme disease

Lyme disease is the most common vector-borne disease in the United States that is often misdiagnosed because of the challenging diagnosis process. This condition is often associated with medical errors because the symptoms it causes are usually non-specific, and it can manifest drastically differently in different illness stages. It mimics many other conditions: erythema migrans, carditis, central nervous system disease, and arthritis. If this condition is diagnosed correctly, it can be cured in 2 to 4 weeks of taking antimicrobials.

Lyme disease

Many doctors believe that the non-specific symptoms caused by this condition’s different stages like arthralgias and excessive tiredness could be a warning that the person should take an antibody test for Lyme disease. However, medical errors can once again occur as the person who gets these tests may receive a false positive, leading to unnecessary treatment that can cause further problems.

MS or Multiple Sclerosis

Neurologists recognize a misdiagnosis of MS as an important issue. This condition is hard to diagnose, and when patients get misdiagnoses of their MS condition, this can only mean that their condition will worsen as more time goes on. Some patients may get misdiagnoses for about 10 or more years. When medical errors are involved with MS, the patient may experience some serious complications.

MS or Multiple Sclerosis