Are you swathed in a blanket while the rest of the world is in tees? While anything from meds to metabolism could be to blame, there’s no need to spend your life shivering. Once you ID the culprit, you’re sure to find the cure.

Lost Pounds

When people lose a considerable amount of weight, they often lose insulating fat and muscle as well, which makes them feel colder, says Tara Gidus, spokesperson for the American Dietetic Association. Resistance training — preferably with light free weights — will help rebuild that body-warming muscle.

Sluggish Glands

If your thyroid is underactive, notes Alan Farwell, M.D., director of patient education for the American Thyroid Association, “your metabolism slows down and you produce less heat.” In addition to goose bumps, symptoms of hypothyroidism include weight gain, constipation, dry skin and fatigue. A simple blood test can determine whether your thyroid’s functioning right; if it isn’t, medication can help you beat the chills.

“Bad” Medicine

The shivers can also be a side effect of certain medications, says Dr. Farwell. It’s common, for instance, to feel cold while taking a blood thinner like Coumadin, though no one has determined why. If your teeth-chattering bouts have coincided with the start of a new pill, ask your doctor about an alternative.

Slowing the Flow

Blood flow, that is. Poor circulation often leads to the chills, but its causes are widespread. Here are a few of the most common:

Iron Issues: When you’re anemic, your body can’t deliver enough red blood cells to your extremities to keep their temperatures in check. Iron-rich foods can help counter the condition, says Gidus, who recommends lean meats, whole grains and legumes.

Raynaud’s Reign: If the slightest chill turns your fingers and toes white, you could have a circulation disorder called Raynaud’s phenomenon, in which blood vessels, which normally “clamp down” against the cold, do so too fast and too hard, limiting blood supply to the skin and causing pain and numbness. It’s usually more of a nuisance than anything else — most people can “thaw” by holding their hands under warm running water, or massaging fingers and feet.

Die-Hard Habits: If you haven’t already done it, cut back on coffee and lose the cigarettes. Both caffeine and smoking constrict blood vessels, slowing circulation and making for
a colder you.