What Are the Causes of Sudden Weight Gain?

The most common cause of weight gain is eating more calories than you consume. However, when certain medical conditions arise, weight gain can occur rapidly, indicating one of numerous potentially serious conditions. If you experience rapid weight gain, seek medical guidance promptly.

Cushing’s Syndrome

Cushing’s syndrome (hypercortisolism) occurs when the body reaps overexposure to a hormone called cortisol. According to the National Endocrine and Metabolic Diseases Information Service, rapid weight gain is a common first symptom of the disorder, which primarily affects adults ages 20 to 50. Additional symptoms of Cushing’s syndrome may include upper body obesity, a rounded face, fat accumulation around the neck, excess body hair growth, fatigue and muscle weakness. Children with Cushing’s syndrome tend to be obese. Use of glucocorticoids—steroid hormones used to treat asthma, rheumatoid arthritis, lupus, and other inflammatory diseases–is a primary cause of Cushing’s syndrome. Obesity, type 2 diabetes and blood sugar problems increase the risk for the condition. If you suspect Cushing’s syndrome as the cause of rapid weight gain, seek guidance and testing from your doctor. Once hormone levels are balanced, generally through medications, surgery or radiation therapy, weight gain and other symptoms often reduce.

Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a hormonal disorder that may cause rapid weight gain in women. According to the U.S. Department of Health and Human Services, PCOS affects as many as 5 million American women. In addition to weight gain, PCOS may cause menstrual problems, hormonal imbalances, acne, depression, sleep problems, excessive hair growth and infertility. Weight gain involved with PCOS accumulates around a woman’s abdomen. When weight gain is intense, PCOS leads to obesity. No known cure exists for PCOS, but it can be managed through a healthy diet, regular physical activity, medications and, in some cases, surgery. Because PCOS increases your risk for diabetes, a dietary lifestyle that supports blood sugar management is key.

Congestive Heart Failure

Congestive heart failure (CHF), or heart failure, occurs when the heart can’t pump enough blood throughout the body. According to the American Heart Association, heart failure may be caused by narrowed arteries, scar tissue from heart attacks, high blood pressure, heart disease or birth defects. When the heart begins failing, it continues to work but less efficiently. When fluid retention (edema) occurs in response to CHF, it results in sudden weight gain. In such cases, swelling appears in the legs and ankles and potentially other body parts as well. If fluid collects in the lungs, it can interfere with breathing, causing breathing problems. Heart failure also reduces the kidneys’ ability to rid the body of sodium and water, which may exacerbate water retention and weight gain.

Heart failure is a serious but potentially manageable condition. If you are overweight, elderly or at risk for heart disease for other reasons, talk to your doctor about how to prevent heart failure and improve your overall health. Sudden weight gain related to CHF may indicate a life-threatening situation. For this reason, seek emergency medical attention as soon as symptoms arise.

About this Author

August J. McLaughlin is a certified nutritionist and health writer with more than nine years of professional experience. Her work has been featured in various magazines such as “Healthy Aging,” “CitySmart,” “IAmThatGirl” and “ULM.” She holds specializations in eating disorders, healthy weight management and sports nutrition. She is currently completing her second cookbook and Weight Limit – a series of body image/nutrition-related PSAs.