How is unexplained weight gain treated?

A clinician may ask when the change began, how quickly it happened, what you eat and drink, your activity, sleep, mood and current medicines. Examination and selected tests can check thyroid function, fluid retention and metabolic health. Weight gain may occur alongside metabolic syndrome, obesity, depression or obstructive sleep apnoea, but the pattern and other symptoms guide the assessment.

Arrange a review if the change is persistent, unexplained or accompanied by swelling, breathlessness, fatigue, low mood, snoring or daytime sleepiness. Bring a list of medicines and supplements, recent weight records and notes about sleep and appetite. Do not stop prescribed medicine abruptly. A weight management programme can combine food, activity, sleep and behaviour support; medication is considered only when clinically suitable.

Get urgent help for sudden swelling with breathlessness, chest pain, severe weakness, confusion, or a rapid change with very little urine. Prompt assessment is also needed for marked thirst and urination, severe mood symptoms or thoughts of self-harm. These warning signs can indicate a problem that needs treatment beyond weight management.

Which causes should we check? Could any medicine be contributing? Do I need thyroid or metabolic tests? Would sleep or mood assessment help? What goals and follow-up plan are realistic for me?