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unexpected weight gain

Diseases that can lead to unexpected weight gain

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There can be many causes of sudden weight gain — both medical and non-medical. Unexplained weight gain without a change in diet or decrease in physical activity can be a serious concern, as the unintentional weight gain may be due to an underlying health condition.

Weight gain, whether rapid or over a period of time, could be the result of fluid retention, abnormal growths, side effects to medication or other health conditions. Here’s a look at some of the potential causes of unintentional weight gain.

Medical conditions

Hypothyroidism: A medical condition in which the thyroid gland is unable to produce enough thyroid hormone, which is responsible for regulating the body’s metabolism. Hypothyroidism may be treated by medication, hormone replacement therapy or lifestyle changes.

Cushing’s syndrome: This condition occurs as a result of prolonged exposure to cortisol, either by cortisol-like medication, or by the presence of a tumor that produces or results in an increased production of cortisol.

Depression: Suffering from depression can lead to weight gain if food is used as a means of comfort or coping. People who suffer from depression often also struggle to find the energy to remain physically active, which can contribute to weight gain.

Insomnia: The body’s circadian rhythm impacts metabolism, which may slow calorie burn, resulting in weight gain. The fatigue that accompanies insomnia also makes it difficult to be physically active.

Congestive heart failure: When the heart can’t pump enough blood to meet the body’s needs, it can cause a buildup of blood and fluid in the feet, ankles and legs, resulting in rapid weight gain.

Hormonal changes

Menstruation: Periodic weight gain often accompanies a woman’s menstrual cycle, as some women experience water retention and blowing during their cycle. Weight gain due to menstruation is typically just a few pounds and weight typically returns to normal when her period ends.

Menopause: As a woman enters the menopause stage, when estrogen levels begin to decline, she may experience weight gain around her stomach and hips.

Polycystic ovarian syndrome: Hormonal changes due to polycystic ovarian syndrome (PCOS) may also cause weight gain.


Unintentional weight gain can be a side effect of certain medications, including:

  • Birth control pills
  • Antidepressants
  • Corticosteroids
  • Antipsychotic medications

The symptoms and effects of weight gain on the body can vary, but most people who experience unexplained weight gain often notice fatigue and discomfort due to the added weight. Shortness of breath, sweating and heart palpitations may also occur.

If you’ve experienced sudden weight gain or are having difficulty breathing, changes in vision or other unexplained symptoms, it may be the sign of a serious health condition. Don’t wait to schedule an appointment with your physician to determine the cause of your weight gain. If you need help losing weight after unintentional weight gain, your doctor may refer you to a First Baptist Medical Center weight loss doctor to discuss the medical interventions that can help you lose weight and reclaim your health.