Does hypothyroidism cause unexplained weight gain?

Thyroid hormone helps regulate how the body uses energy. When levels are low, energy use may slow and fluid retention can contribute to a change on the scales. People may also notice tiredness, feeling cold, dry skin, constipation, low mood, or slower thinking.

Weight change can also relate to eating patterns, activity, sleep, stress, medicines, fluid shifts, or other hormonal and medical conditions. The amount and speed of change do not confirm a thyroid cause, so a broader assessment is useful.

Make an appointment if weight gain is persistent or comes with cold sensitivity, constipation, marked tiredness, hair changes, or a slower heartbeat. Bring a list of medicines and supplements, and note when the change began and what other symptoms appeared.

A clinician can examine you and request thyroid blood tests when appropriate. Keep meals regular and choose comfortable, sustainable activity while waiting for review. Avoid crash diets and do not use thyroid hormone for weight loss unless it has been prescribed for a confirmed need.

Seek urgent care for weight change with severe breathlessness, chest pain, fainting, confusion, extreme drowsiness, or rapidly worsening swelling. Arrange prompt medical advice if you are pregnant, recently started a medicine, or have swelling with reduced urine output.

Could hypothyroidism explain my symptoms? Which thyroid tests should I have? Could a medicine or another condition be contributing? What changes should I track, and when should we review the plan?