Numerous conditions can cause sudden, unintentional weight gain. According to the MedlinePlus website, unintentional weight gain is an increase in your body weight that occurs when you consume more calories than your body uses. In some cases, unintentional weight gain is caused by certain lifestyle factors or a medical condition, such as an endocrine disorder. If you experience rapid, unintentional weight gain, you should consider consulting your physician for an evaluation or assessment.
Hypothyroidism is an endocrine condition that can cause you to gain weight suddenly. According to the University of Maryland Medical Center, hypothyroidism occurs when your thyroid gland--the butterfly-shaped gland that is located at the front of your neck--fails to produce sufficient amounts of thyroid hormone. The UMMC states that there are several types of hypothyroidism, although the most common is Hashimoto's thyroiditis, an autoimmune condition in which your immune system mistakenly attacks your thyroid gland. Although hypothyroidism can affect people of all ages and genders, it usually manifests in women over the age of 50. Common signs and symptoms associated with hypothyroidism include decreased pulse, fatigue, hoarse voice, goiter, cold intolerance, sudden weight gain, constipation, numbness in your extremities, headaches and menstrual problems.
Polycystic ovary syndrome can cause sudden weight gain. MayoClinic.com states that PCOS is the most common hormonal disorder affecting women of reproductive age. PCOS is named for the appearance of the ovaries in most, but not all, women with this condition. In most women with PCOS, the ovaries are enlarged and contain many small cysts--fluid-filled sacs--located along their outer edges. Although the exact cause of PCOS is unknown, factors that may contribute to the condition include excess insulin, low-grade inflammation, heredity and abnormal fetal development. Common signs and symptoms associated with PCOS include sudden weight gain, menstrual abnormalities, excess androgen or male hormone and polycystic ovaries. Possible complications associated with PCOS include type 2 diabetes, hypertension and endometrial cancer.
Cushing's syndrome is a hormonal disorder that can cause sudden weight gain. According to the National Institute of Diabetes and Digestive and Kidney Diseases, or NIDDK, Cushing's syndrome, also known as hypercortisolism, is caused by prolonged exposure of your tissues to the hormone cortisol. Cushing's syndrome is a relatively rare condition. Most people who develop Cushing's syndrome are between 20 and 50 years of age. If you have type 2 diabetes and elevated blood pressure, you may have a greater likelihood of developing Cushing's syndrome. The NIDDK states that common signs and symptoms associated with Cushing's syndrome include sudden weight gain, extreme fatigue, weak muscles, elevated blood pressure, elevated blood glucose, increased thirst, irritability, anxiety, depression and a fatty hump between your shoulders.