Underactive Thyroid: UK Online Doctor & Levothyroxine Guide
Educational information — not medical advice.
This article was prepared by the OnlineDoctor24 editorial team and reviewed for factual accuracy against UK clinical guidance (NHS and NICE). It is not written by a doctor and does not replace personal medical advice. For symptoms specific to you, book an online doctor consultation.
Key points
- Hypothyroidism is common, especially in women over 40.
- Diagnosis is based on raised TSH with low free T4.
- Levothyroxine is highly effective and safe.
- Annual TSH monitoring is standard.
Symptoms
- Fatigue.
- Weight gain.
- Cold intolerance.
- Constipation.
- Dry skin and hair, hair loss.
- Low mood.
- Heavy periods.
- Slowed thinking.
Diagnosis
TSH is the screening test. Raised TSH + low free T4 = primary hypothyroidism. Subclinical (raised TSH, normal T4) is treated if TSH >10 or symptoms present. Thyroid antibodies (TPO) confirm autoimmune (Hashimoto's) cause.
Treatment
Levothyroxine, taken on an empty stomach 30–60 min before food (or at bedtime ≥3h after eating). Avoid taking with calcium, iron, PPIs or coffee — they reduce absorption. Recheck TSH 6–8 weeks after dose changes.
Online care
An online GP can interpret thyroid blood tests, prescribe and titrate levothyroxine and arrange repeat blood tests.
Frequently asked questions
Common questions UK patients ask about hypothyroidism.
How an online doctor can help
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This article is for general information only and does not replace personal medical advice from a qualified doctor. Content is reviewed against UK NHS and NICE guidance by the OnlineDoctor24 editorial team and is not authored by a medical doctor. If your symptoms worsen or you are unsure, please book a consultation with a GMC-registered GP.
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