Feeling Cold All the Time After a Gastric Bypass

Gastric bypass, a type of weight-loss surgery, helps morbidly obese patients lose weight by reducing the stomach to an egg-sized pouch and rerouting the digestive system to block some calorie absorption. As a result of the weight loss, changes in metabolism and possibly nutritional deficiencies -- especially during the first 6 months after surgery -- patients may complain of feeling cold.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Cold Intolerance

If you need a sweater when everyone around you is comfortable, you may have a condition called cold intolerance. Possible causes may include anemia, blood vessel problems such as Raynaud's phenomenon, anorexia nervosa or disorders of the thyroid. Individuals with severe chronic illnesses and those without sufficient stores of fat also have difficulty regulating body heat in cold environments. The treatment regimen depends on the underlying cause of the problem.

Rapid Weight Loss

Patients lose weight rapidly during the first six months after gastric bypass. In fact, they lose about 0.5 to 1 lb. a day for the first 90 days for a total of 40 to 90 lbs., says Jeffrey Mechanick, M.D., lead researcher in a study published in the September 2008 issue of "Surgery for Obesity and Related Diseases." During that time, their metabolism slows and they lose the fat stores that normally insulate them against cold temperatures.


Gastric bypass patients may experience iron deficiency anemia, because they eat less and their smaller stomachs produce less of the hydrochloric acid needed to absorb iron. Iron deficiency may cause cold intolerance, hair loss, fatigue, reduced immune function and a penchant for chewing ice, according to Dana Swilley, R.D., in an article published in the March 2008 issue of "Bariatric Times." Other symptoms may include weakness, dizziness, irritability, shortness of breath, pale skin, brittle nails, chest pain, irregular heartbeat or coldness in your hands or feet.


Iron deficiency may occur in as many as 20 to 40 percent of gastric bypass patients, according to Linda Aills, R.D., lead researcher in a study published in the September 2008 issue of "Surgery for Obesity and Related Diseases." To prevent cold intolerance due to iron deficiency, follow your surgeon's instructions regarding supplements and laboratory testing. During the period of rapid weight loss, relieve the discomfort of cold intolerance by wearing socks even in bed, wearing a hat and gloves in cold weather and dressing in layers.