Your Thyroid Could Be the Hidden Cause of Fatigue, Weight Gain or Mood Swings

Author: Tharb Faisl

Your thyroid may be small — but its impact on your overall health is massive. From energy levels, weight, and mood, to digestion, a well-functioning thyroid is essential for daily wellbeing.

At Marylebone Diagnostic Centre, we offer private thyroid blood tests in London — with fast, accurate results and no referral needed.

🔗 Explore our full Thyroid Testing Services

What Is the Thyroid?

The thyroid gland sits in your neck and produces two essential hormones:

• T3 (Triiodothyronine)
• T4 (Thyroxine)

These hormones regulate your:

• Metabolism
• Body temperature
• Heart rate
• Concentration & mood
• Digestion

When thyroid levels are out of balance, symptoms often arise. A private thyroid blood test helps identify whether your symptoms are due to hypothyroidism (underactive) or hyperthyroidism (overactive).

Symptoms of Thyroid Imbalance

Underactive Thyroid (Hypothyroidism):

• Ongoing fatigue
• Weight gain despite no lifestyle changes
• Low mood or signs of depression
• Cold hands and feet
• Hair thinning or hair loss
• Constipation

Overactive Thyroid (Hyperthyroidism):

• Rapid or unexplained weight loss
• Anxiety or increased irritability
• Racing heart rate
• Sweating and heat intolerance
• Difficulty sleeping
• Tremors or shakiness

Read more on NHS Thyroid Conditions for background on diagnosis and treatment.

What’s Included in Our Private Thyroid Blood Test?

Our core thyroid blood test panel includes:

• TSH (Thyroid-Stimulating Hormone) – first-line screening
• Free T4 (Thyroxine) – active thyroid hormone
• Free T3 (Triiodothyronine) – key for metabolism

We also offer advanced thyroid panels, which may include:

• Thyroid antibodies (TPO, TGab): important in autoimmune thyroid issues like Hashimoto’s or Graves’ disease
• Reverse T3: tested in chronic fatigue or complex thyroid cases

Learn more from the British Thyroid Foundation about thyroid health.

Why Choose a Private Thyroid Blood Test at Marylebone Diagnostic Centre?

✅ Walk-in appointments near Paddington & Marylebone
✅ No GP referral required
✅ Same-day slots available
✅ Fast results in 1–2 working days
✅ Trusted by GPs, endocrinologists, and integrative medicine specialists

We offer both routine thyroid testing and in-depth hormonal assessments to help you find answers faster.

💬 “I had been feeling tired for months. A simple thyroid blood test revealed low T3. The treatment changed everything.” – London patient

Want a Broader Health Check?

Many clients combine their private thyroid blood test with:

• Vitamin D test
• Iron & B12 screening
• Female hormone panel
• Full blood count
• Liver and kidney function tests

We can build a custom test package tailored to your symptoms and goals — ideal for those with fatigue, hormonal imbalances, or metabolic concerns.

Check out our custom health packages to learn more.

Book a Private Thyroid Blood Test in London Today

Don’t wait for symptoms to worsen. A private thyroid blood test can provide early answers and peace of mind.

📍 Book online at marylebonediagnosticcentre.com
📞 Or call our friendly team for same-day availability 02077240540 / 07495970109

🔗 Learn about all the profiles we provide
🔗 Visit Thyroid UK for support and awareness

Take control of your health — one test can make all the difference.