Thyroid Problems: Symptoms You Should Not Ignore, Tests You Need, and Where to Get Checked in London

Last Updated: March 2026 | Medically Reviewed by GMC-Registered Doctors at The Online GP by The Wellness

Thyroid disorders affect approximately 1 in 20 people in the UK, with women being 5 to 10 times more likely to be affected than men. Despite being one of the most common endocrine conditions, thyroid problems are frequently missed — sometimes for years — because their symptoms overlap with so many other conditions.

Fatigue? Could be stress. Weight gain? Could be diet. Hair loss? Could be ageing. Brain fog? Could be sleep deprivation. These are all thyroid symptoms — and a simple blood test can tell you whether your thyroid is the cause.

This guide explains the symptoms of thyroid problems, which tests you actually need (not just the one most NHS GPs order), when a thyroid ultrasound is essential, and how to get investigated quickly in London.

Understanding Your Thyroid

The thyroid is a butterfly-shaped gland at the front of your neck that produces hormones controlling your metabolism — essentially how fast every cell in your body works. When your thyroid produces too little hormone (hypothyroidism or underactive thyroid), everything slows down. When it produces too much (hyperthyroidism or overactive thyroid), everything speeds up.

Hashimoto's thyroiditis (autoimmune hypothyroidism) is the most common cause of underactive thyroid in the UK. Graves' disease is the most common cause of overactive thyroid. Both are autoimmune conditions where your immune system attacks your thyroid gland.

Symptoms of an Underactive Thyroid (Hypothyroidism)

An underactive thyroid causes your metabolism to slow, producing symptoms that develop gradually over months or years. This gradual onset is precisely why the condition is so often missed — patients adapt to feeling progressively worse and assume it is normal.

Common symptoms include persistent fatigue and low energy despite adequate sleep, unexplained weight gain or difficulty losing weight, feeling unusually cold when others are comfortable, dry skin and brittle nails, hair thinning or hair loss (including the outer third of the eyebrows), constipation, brain fog and poor concentration, low mood or depression, muscle aches and weakness, heavy or irregular periods, reduced libido, and a puffy face, particularly around the eyes.

Symptoms of an Overactive Thyroid (Hyperthyroidism)

An overactive thyroid accelerates your metabolism, causing symptoms that can be dramatic or subtle.

Common symptoms include unexplained weight loss despite normal or increased appetite, anxiety, nervousness, or irritability, rapid or irregular heartbeat (palpitations), tremor (fine shaking of the hands), heat intolerance and excessive sweating, difficulty sleeping, frequent bowel movements or diarrhoea, muscle weakness particularly in the thighs and upper arms, lighter or absent periods, and eye problems (bulging, grittiness, or double vision — particularly in Graves' disease).

The Testing Gap: Why TSH Alone Is Not Enough

Here is something important that many patients do not know. When you see an NHS GP with symptoms suggestive of thyroid dysfunction, they will typically order a TSH (thyroid stimulating hormone) test. If TSH is within the normal range, they may tell you your thyroid is fine.

TSH is an excellent screening test, but it does not tell the whole story. A comprehensive thyroid assessment requires three tests:

• TSH — the pituitary hormone that tells the thyroid how hard to work

• Free T4 (thyroxine) — the main hormone your thyroid produces

• Free T3 (triiodothyronine) — the active thyroid hormone that cells actually use

TSH alone can miss subclinical thyroid disorders, where TSH is borderline but T4 and T3 are already abnormal. It can also miss central hypothyroidism (a pituitary problem rather than a thyroid problem), where TSH may appear normal despite genuinely low thyroid hormone levels.

Additionally, thyroid antibodies (anti-TPO and anti-thyroglobulin) should be tested if autoimmune thyroiditis is suspected. Elevated antibodies confirm autoimmune thyroid disease and predict future thyroid failure — allowing earlier intervention.

At The Online GP by The Wellness, our doctors routinely order the full thyroid panel — not just TSH — because a partial answer can be worse than no answer at all.

Think your thyroid might be the problem? Get a comprehensive thyroid blood test — not just TSH. Same-day GP consultations from £49. Thyroid ultrasound from £195.

📱 Book a Thyroid Check via WhatsApp 📧 Email: team@thewellnesslondon.com

When Do You Need a Thyroid Ultrasound?

Blood tests tell you how your thyroid is functioning. A thyroid ultrasound tells you what your thyroid looks like — and that information is essential in several clinical scenarios.

You should have a thyroid ultrasound if you have:

• A visible or palpable lump or swelling in your neck

• A thyroid nodule found on examination

• Abnormal thyroid blood tests (to assess the gland structure)

• Difficulty swallowing or a sensation of something pressing on your throat

• Hoarse voice without an obvious cause

• Enlarged cervical lymph nodes

• Family history of thyroid cancer

• Previous radiation exposure to the head or neck

Thyroid nodules are remarkably common — studies suggest they are present in up to 50% of adults when ultrasound is used for screening, with the vast majority being entirely benign. However, a small percentage (approximately 5–10%) require further investigation to exclude malignancy. Ultrasound characterises nodules by their size, shape, echogenicity, borders, and vascularity — features that determine whether fine needle aspiration (FNA) biopsy is recommended.

Thyroid Ultrasound at The Wellness

At The Wellness, thyroid ultrasound is performed by a GMC-registered doctor — not a sonographer. This means the person scanning you has the clinical knowledge to assess nodule characteristics, correlate findings with your blood tests and symptoms, and make immediate clinical decisions about next steps.

Thyroid & Neck Ultrasound Price Guide – The Wellness (London, 2026)

• Thyroid Ultrasound: £195

• Neck Lymph Node Assessment: £195

• Thyroid and Neck Combined Scan: £265

Your doctor explains findings during the scan, provides a verbal debrief, and sends your written report within 2 hours. If a nodule requires further investigation, referral to an endocrinologist or thyroid surgeon is arranged the same day.

The Complete Thyroid Investigation: From Symptoms to Answers

Here is how to get a thorough thyroid investigation through The Online GP by The Wellness.

Step 1: GP consultation (from £49). Discuss your symptoms with a GMC-registered doctor. Your doctor examines your neck (in-person or refers to in-person examination if initial consultation is by video/phone), reviews your medical history, and arranges the right tests.

Step 2: Comprehensive thyroid blood panel. TSH, Free T4, Free T3, and thyroid antibodies — the full picture, not just TSH. Results within 24–48 hours.

Step 3: Thyroid ultrasound (£195) if indicated. Doctor-performed, same-day results, immediate clinical interpretation.

Step 4: Diagnosis and treatment plan. Your doctor integrates blood results, ultrasound findings, and clinical assessment to provide a definitive diagnosis and treatment plan. This may include thyroid medication (levothyroxine for underactive thyroid, carbimazole for overactive), specialist referral if needed, or reassurance with a monitoring plan.

The entire process — from first consultation to diagnosis — can be completed within a week. Compare this to the NHS pathway, where initial GP appointment, blood test appointment, blood test results, referral for ultrasound, ultrasound appointment, ultrasound report, and follow-up appointment to discuss results can stretch to months.

Your thyroid controls your energy, weight, mood, and metabolism. Do not guess — test.

📱 Book Your Thyroid Assessment via WhatsApp 📧 Email: team@thewellnesslondon.com

The Online GP by The Wellness — Comprehensive thyroid blood tests and doctor-performed thyroid ultrasound from £195. Same-day results. No referral needed.

Frequently Asked Questions

What are the early symptoms of thyroid problems? Early symptoms include persistent fatigue, unexplained weight changes, hair thinning, feeling unusually cold or hot, mood changes, dry skin, constipation, irregular periods, brain fog, and muscle weakness. Because these symptoms develop gradually and overlap with many other conditions, thyroid disorders are frequently missed for months or years.

What blood tests check thyroid function? A comprehensive panel includes TSH, Free T4, and Free T3. Thyroid antibodies (anti-TPO, anti-thyroglobulin) should be added if autoimmune thyroid disease is suspected. Many NHS GPs initially test only TSH, which can miss subclinical disorders.

When do you need a thyroid ultrasound? When there is a visible or palpable lump, thyroid nodule, abnormal blood tests, difficulty swallowing, unexplained hoarseness, enlarged lymph nodes, or family history of thyroid cancer. Thyroid ultrasound at The Wellness costs £195, performed by a GMC-registered doctor with same-day results.

How much does a private thyroid test cost in London? A GP consultation to arrange thyroid blood tests starts from £49 at The Online GP. Thyroid ultrasound costs £195. A combined thyroid and neck ultrasound costs £265. All scans include doctor verbal debrief and written report within 2 hours.

Can an underactive thyroid be cured? Autoimmune hypothyroidism (Hashimoto's) is managed with daily levothyroxine, a synthetic thyroid hormone replacement. With correct dosing, patients achieve normal thyroid levels and resolution of symptoms. It is a lifelong treatment but highly effective. Your doctor monitors levels with regular blood tests and adjusts dosing accordingly.

Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. All content has been reviewed by GMC-registered doctors at The Online GP by The Wellness.

Sources: British Thyroid Foundation; NICE CKS — Hypothyroidism and Hyperthyroidism (2025); British Thyroid Association Guidelines for Thyroid Nodule Management (2024); Garmendia Madariaga et al., Thyroid (2014).