Weird Symptoms, Explained

You Get Foot Cramps at Night

The explanation: A subtle electrolyte imbalance (involving potassium, magnesium, or calcium) or mild dehydration may be triggering these cramps, says Teng.
The fix: Get up and walk around, then massage the muscle to help it relax.
When to see a doctor: If you get them nightly or during the day when you walk. A condition such as a blood-clotting disorder or nerve damage could be to blame.

Your Foot Goes Numb When You’re on the StairMaster

The explanation: When you move your feet in a repetitive way during a workout, or if your shoes or laces are too tight, the “tiny nerves between your toes can get pinched as you put pressure on your foot,” says Sabrina Strickland, an orthopedic surgeon at the Hospital for Special Surgery, in New York City, and that can make it feel uncomfortably numb.
The fix: During your workout, wiggle your toes in your shoes a few times—and loosen your laces if they’re too tight.
When to see a doctor: If numbness happens during other activities or you can’t make it go away. You could have a nerve problem in your foot.

Your Body Jerks as You Fall Asleep

The explanation: These hypnic jerks, or sleep starts, probably stem from nerves misfiring as your brain and body downshift into sleep mode. “An interruption in your brain’s signal to your body to relax can cause the limbs and head to jerk,” says Clete A. Kushida, M.D., the medical director of the Stanford Sleep Medicine Center, in Redwood City, California.
The fix: There’s nothing you can do to prevent these harmless jerks. Fortunately, they last only a few seconds.
When to see a doctor: If they happen frequently or disturb your sleep, as they might be a sign of sleep apnea or periodic limb movement disorder.