What Will a Blood Test Reveal About Your Health?
Blood tests are one of the simplest yet most powerful tools for understanding your health. With just a small sample, clinicians can measure hormone levels, nutrient status, and markers of organ function, each providing valuable insight into longevity and wellbeing.
Here’s what blood tests can reveal, and what action you might take based on the results.
Thyroid Function
What it measures: Thyroid tests usually look at thyroid stimulating hormone (TSH) and, in some cases, free T4 and free T3.
Why it matters: The thyroid regulates metabolism, energy, mood, and body temperature. An underactive thyroid (hypothyroidism) can cause fatigue, weight gain, and low mood, while an overactive thyroid (hyperthyroidism) can lead to weight loss, anxiety, and heart palpitations.
What you can do: If results are abnormal, treatment may include thyroid hormone replacement (for hypothyroidism) or medications to reduce thyroid activity. Lifestyle changes: ensuring adequate iodine, selenium, and iron intake — also support thyroid function.
Testosterone and Other Hormones
What it measures: In men, testosterone levels are often checked to assess energy, libido, and muscle health. In women, oestrogen, progesterone, and testosterone may be measured to evaluate menstrual health, fertility, or symptoms such as fatigue and hair loss.
Why it matters: Low testosterone in men has been linked to reduced bone density, muscle mass, and mood changes. In women, imbalanced hormones can affect cycles, fertility, and long-term cardiovascular health.
What you can do: If levels are low, clinicians may investigate underlying causes (such as stress, sleep, or chronic illness). In some cases, hormone replacement therapy may be considered. Regular exercise, adequate sleep, and balanced nutrition (especially protein and healthy fats) support hormonal health.
Vitamin D
What it measures: Vitamin D (25-hydroxyvitamin D) levels in the blood reflect your body’s status of this essential nutrient.
Why it matters: Vitamin D supports bone strength, muscle function, and immune health. Low levels are common in the UK, especially in winter, and are associated with increased risk of osteoporosis and infections.
What you can do: Supplementation is often recommended between October and April in the UK, when sunlight exposure is limited. Safe sun exposure and vitamin D-rich foods (oily fish, eggs, fortified products) can also help.
Iron and Ferritin
What it measures: Ferritin reflects the body’s iron stores, while serum iron and transferrin saturation provide a fuller picture.
Why it matters: Iron is vital for oxygen transport. Low levels can cause anaemia, leading to fatigue, weakness, and reduced exercise capacity. Conversely, excess iron can damage organs over time.
What you can do: If low, dietary changes (red meat, beans, lentils, leafy greens) or supplementation may be prescribed. If high, further investigation is important to rule out conditions such as haemochromatosis.
Why It Matters for Longevity
Regular blood testing helps detect subtle imbalances before they become major health issues. Early detection of nutrient deficiencies, thyroid dysfunction, or hormonal imbalances allows for targeted interventions that can improve energy, mood, and long-term health.
Takeaway
A blood test is not just about numbers on a page. It’s a snapshot of how your body is functioning and where you can take action to support wellness and longevity. Discussing your results with a healthcare professional is essential before making any changes, but knowing what these markers mean puts you in a stronger position to take charge of your health.
If you want to discuss anything mentioned on this blog, email us at team@thewellnesslondon.com, let’s talk!
~ The Wellness