If you get weak or numb in your arm, leg, or face, it can be a sign of a stroke, especially if it's on one side of your body.
You could also be having a stroke if you can't keep your balance, feel dizzy, or have trouble walking.
Get help quickly if you suddenly can't see well, get a bad headache, feel confused, or have problems speaking or understanding.
"Caught early, it is often reversible," says internist Jacob Teitelbaum, MD.
Don't wait to see a doctor. Call 911. If you get a clot-buster drug within 4.5 hours of your first symptom, you can lower your risk of long-term disability from stroke.
2. Chest Pain
When it comes to chest pain, it's better to be safe than sorry.
"Any chest pain, especially accompanied by sweating, pressure, shortness of breath, or nausea, should be evaluated by a medical professional right away," says Shilpi Agarwal, MD, with One Medical Group in Washington, DC.
Chest pain or pressure can be a sign of heart disease or a heart attack, particularly if you feel it after being active. It may also mean that you have a blood clot moving into your lung, Teitelbaum says.
If your chest feels tight or heavy, and it lasts more than a few minutes or goes away and comes back again, get help. Don't try to tough it out.