If a doctor gets a diagnosis wrong, misses a life-threatening condition, or gives a belated diagnosis, patients can suffer severe injury or illness. Some patients even die of preventable causes. But this does not necessarily make this a case of malpractice. In order to justify a medical malpractice lawsuit, a plaintiff must first prove that there was a doctor-patient relationship, that the doctor was unreasonably incompetent, and that this negligence is the cause of their suffering. The difficulty can lie in proving that the doctor's diagnostic mistake was in fact an instance of negligence. It can be even trickier to prove that this negligence (not a preexisting condition) is the cause of suffering.

The problem is that even the most experienced doctor will still get a diagnosis wrong from time to time. To diagnose a patient, a doctor will use "differential diagnosis", creating a list of possible diagnoses that are ordered according to how well they account for the patient's symptoms. The list is whittled down and refined after looking into the patient's medical history, testing for possible conditions, sending the patient to a specialist, etc. Hopefully, only one possible diagnosis will remain after all these examinations, but this cannot always be the case. If a doctor makes a mistake in the diagnosis, it is not negligent unless he or she failed to include a diagnosis on the list of possibilities that a reasonably competent doctor would not have excluded. Or if the doctor did have this diagnosis on the list, but he or she did not look further into it through tests or referrals, then this might be negligence too.

Perhaps the missed diagnosis or misdiagnosis came from a mistaken test. This could mean that a machine was defective, or that there was a mishandling or misreading of the test. In this instance, a doctor is probably not responsible. If you can prove negligence though, someone else could be liable, such as a technician or a specialist.

Here are some ways that a negligent doctor can cause harm through a mistaken diagnosis:

• It is possible that a doctor misdiagnosed a patient. This could mean telling a healthy patient that he has cancer, or telling someone that she has a digestive issue when she in fact has cancer.
• A doctor may fail to give any diagnosis at all, entirely missing a medical condition that the patient has.
• One of the most typical mistakes is coming up with the right diagnosis, but doing so late, and perhaps the delayed diagnosis is too late.
• Perhaps the doctor diagnosed you correctly, but then did not stay on top of complications you suffered, failing to take them into account.
• Perhaps a doctor missed one part of a diagnosis. He or she could have given one right diagnosis, but failed to diagnose a related or unrelated disease.

But again, proving negligence is not enough. You also have to prove that this negligence is responsible for your injury or exacerbated injury. If we take the instance of a late cancer diagnosis, then you could prove that this forced you to endure harsher medical treatment and to suffer poorer health. If a loved one died because it was too late to treat the cancer, then this could be malpractice too. There are even strange cases of a doctor giving a false diagnosis, saying that you have a condition that you in fact do not. This can cause a great deal of mental anguish as well as financial hardship as you pay for medical care that you do not need. It can cause needless physical suffering too. If you believe that you or a loved one's diagnostic error was due to negligence, then contact a medical malpractice attorney today to see if you have a case.