There are a lot of things that you can do
to avoid or reduce the risk of a wrong diagnosis:
See a doctor: The majority of doctor's diagnoses are correct
and are far more likely to be accurate than your own.
Never self diagnose based on the Internet, books, or amateur advice.
Doctors are trained to see signs that patients do not.
Never avoid seeing a doctor based on your own suspicions.
It is common for patients to visit doctors assuming that they have
a terrible disease, only for the doctor to find out it is not the case.
See a specialist: A trained specialist is even less likely
to make a wrong diagnosis than your family doctor.
Get a second opinion: Getting the opinion of two or more doctors
makes the chances of a wrong diagnosis even lower.
If the two diagnoses match, then the chances of a wrong diagnosis
are much lower.
And if they don't match, then there is a puzzle to solve to get
to the correct diagnosis.
Ask for a diagnosis:
Ask your doctor to explicitly name the condition
that is their diagnosis.
You have to do this because sometimes the doctor won't actually tell you what the name
of the condition they suspect.
The reasons for a doctor doing this are not usually intentionally
misleading, but are more like not wanting to scare you with a serious
sounding name, thinking you won't understand it anyway,
or that you don't want to know.
In fact, many patients don't want to know, but just
want the doctor to tell them what to do (i.e. what treatments to use).
However, if you want to be clear on the diagnosis,
you need to have it clearly set out.
Ask questions: It is hard to assess the accuracy of your diagnosis
unless you understand what it is, and why it is given.
Exactly what is the diagnosis? How sure is your doctor? What tests has your doctor done?
Are any other diagnoses possible?
What other diagnoses has your doctor ruled out?
Are any extra complications possible?
What other related diseases are possible?
Which ones have been tested for or ruled out?
Repeat laboratory or pathology tests: Not only the doctor can make a mistake,
but the laboratory tests may be wrong
due to a false negative or false positive.
This happens rarely, but can be very severe,
particularly if your diagnosis is strongly based on one test result.
Doctors tend to trust laboratory tests because they are rarely wrong.
There are several possible methods to reduce your risk of a wrong diagnosis
based on a wrong test.
Repeat the same test: This reduces the likelihood of a simple laboratory error
or administrative mixup, since it shouldn't happen twice.
Different tests: If there are multiple diagnostic tests for your disease,
consider having another type of test done.
Different brand of the same tests: Sometimes the test itself may be faulty,
giving a false positive or a false negative in a small percent of cases.
Research your particular test and see if there may be an alternative.
Different laboratory or technician: If you don't trust your test results,
you might want to get them repeated at a different laboratory.
Read test documentation: Always read the fine print about a particular test.
All tests have known failures,
where they can register a false positive or a false negative.
Your doctor may not be familiar with all the obscure rare conditions
under which a test may fail.
Always make sure you're not in the rare situation where a test may be the wrong test.
Research your disease: The best way to feel confident in your diagnosis
is to understand what is happening.
Research your disease, how it is diagnosed, and what tests are typical.