Diseases like Down’s syndrome and Ménière’s disease are shifting to drop the possessive noun, so you might hear Down syndrome, Ménière disease, Alzheimer disease, etc.
Doctors listen to symptoms then make a “differential diagnosis”, which is essentially a working theory. They then test the theory to confirm the diagnosis. (A “differential diagnosis” differentiates one particular disease from other diseases that present similar symptoms; e.g., “it could be brain cancer or a stroke—differential diagnosis is stroke.”)
Doctors should start with the most specific symptoms. For example, “stomach ache” could be caused by hundreds of conditions while “a large lump in my abdomen” has fewer causes.
Modern CPR recommendations are to lay the patient flat and begin aggressive chest compressions—no rescue breaths—while getting others to call 911 and seek an automated external defibrillator (AED). AEDs are becoming more common. They instruct laypeople how to proceed and administer shocks as needed.
Unexplained weight loss means your body is not absorbing nutrients properly or is burning calories in an unexplained way. Diabetes and cancer are common causes.
Don’t assume that your doctors are communicating. Make sure that records are shared between them and that they know about one another.
In emergency situations doctors use their A, B, Cs: Airway, Breathing, Circulation, Disability, Exposure. These are handled in sequence. The technique is meant to make a complex problem more tractable. If a patient has a blocked airway, they first intubate (or whatever is appropriate); if airway is clear they ensure the patient is breathing, then that the patient’s heart is working and the patient is not losing blood. Disability assesses the patient’s general competency, usually using the AVPU method, where the patient is graded as alert (A), voice responsive (V), pain responsive (P), or unresponsive (U). This is an alternative to the Glasgow Coma Scale, which uses six levels of eye, verbal, and motor (EVM) responses. Exposure is about a more general physical exam, looking for signs of trauma.
They think King Tut died of sickle-cell disease (a.k.a. sickle-cell anemia). Sickle-cell carriers are resistant to malaria, so it’s a great trait to have in places where malaria is a leading cause of death; however, sickle-cell is more likely to kill so the benefits are lost if a child inherits. (Sickle-cell is inherited in an autosomal recessive pattern where two carrier parents have a ¼ chance for the child to be unaffected, 2/4 chance for the child to be a carrier, and ¼ chance for the child to have sickle-cell.)