Fluid retention, or edema, and certain medications are possible causes of sudden, unintentional weight gain, according to Healthline. Other potential causes of unintentional weight gain include pregnancy, menstruation and hormonal changes.
Unintentional weight gain means a person does not consume higher amounts of foods or liquids than usual and still gains weight, explains Healthline. Fast, unintentional weight gain is often a sign of a severe medical condition. People with edema tend to experience swelling in the face, hands, feet, limbs or stomach. Those with kidney failure or heart failure usually suffer fluid retention.
Pregnancy is a common cause of continuous, unintentional weight gain, and it involves excess weight consisting of the baby, placenta, enlarging uterus, higher blood supply and amniotic fluid, states Healthline. Women between 45 and 55 years old enter a menopausal stage, in which lower estrogen levels lead to weight gain around the hips and abdominal area. Middle-aged individuals also typically experience weight gain due to slower metabolism resulting from hormonal changes. Higher cortisol levels, hypothyroidism and Cushing syndrome are other hormonal conditions related to weight gain.
Medications that can cause weight gain include birth control pills, antipsychotic medications, antidepressants and corticosteroids, notes Healthline. It is crucial to see a doctor immediately if a person experiences rapid weight gain, particularly with accompanying symptoms such as swollen feet, breathing trouble, breathlessness, sensitive skin or fever.