What are the symptoms of an underactive thyroid?

An underactive thyroid (hypothyroidism) is where your thyroid gland does not produce enough hormones. Common symptoms include tiredness, weight gain, feeling cold, dry skin, thinning hair, muscle aches, depression, and a slow heart rate. It is more common in women and runs in families. Diagnosis is made with a simple blood test measuring TSH and T4 levels. Treatment is daily levothyroxine tablets, which you will need for life.

I had exactly these symptoms and it took 2 years to get diagnosed because I kept being told it was stress. Push your GP for a full thyroid panel blood test — not just TSH, but also free T4 and thyroid antibodies. Once I started levothyroxine, it took about 6-8 weeks to feel a difference, but now I feel completely normal. The weight came off gradually too.

This is an important metabolic & endocrine question. We recommend speaking with your GP for personalised advice. You can also contact NHS 111 (free, 24/7) for urgent guidance, or visit nhs.uk for trusted health information. Please note: this is general health information, not a substitute for professional medical advice.