❶ SLURRED SPEECH

Every 40 seconds, someone in the United States has a stroke, says the CDC. And about 87 percent of those are life-threatening ischemic strokes, in which blood flow to the brain is blocked. If you experience slurred speech, facial drooping or arm weakness (especially on one side of the body), call 911 immediately—the sooner treatment is received (60 minutes is considered the “golden hour” among physicians), the less likely damage will be permanent.

❷ EXTREME FATIGUE

There’s a difference between feeling tired and feeling constant fatigue, defined as lacking energy consistently or being worn out after simple activities. Your body may be warning you of heart problems. The American Heart Association found that 71 percent of female heart attack survivors reported feeling unexplained fatigue in the weeks prior. If your exhaustion is new or dramatic, talk to your doctor.

❸ MOLE CHANGES

Follow these ABCDES of skin cancer from the American Academy of Dermatology, and be sure to consult a doctor if your moles are exhibiting any of the below: Asymmetry (is one half unlike the other?), Border (are the edges irregular or scalloped?), Color (does the spot have varying colors from one area to the next?), Diameter (is it the size of a pencil eraser or larger?) and Evolution (is it morphing in size, shape or color?).

❹ CONSTANT THIRST

While thirst is the brain’s way of warning your body of dehydration, unquenchable thirst (even after drinking water) could be a sign of diabetes— especially paired with frequent urination. That’s because high blood-sugar levels force the kidneys to work overtime, excreting glucose into the urine and pulling fluids from your body along with it.

❺ SWOLLEN ANKLES

If your legs or ankles are persistently swollen (not just after a long day of standing or walking outside), it could mean your heart isn’t efficiently pumping blood. In fact, pedal edema (foot and ankle swelling) is one of the cardinal signs of congestive heart failure. Call your doctor if it’s accompanied by other symptoms, such as shortness of breath.