Your 40s are a pivotal decade. Hormones shift, iron status changes, cardiovascular risk quietly rises, and symptoms that were once minor can become significant. The right blood tests at this stage aren't just reassuring — they're actionable.
Why 40 Is the Right Time to Start Checking
For most women, significant hormonal change starts in the early 40s — sometimes as early as 38. Perimenopause is not a single event but a gradual transition that can span 8–10 years. At the same time, the cardioprotective effect of oestrogen begins to wane, and metabolic health becomes increasingly important. A targeted blood test panel gives you a baseline — and catches problems before they become symptoms.
The Essential Panel for Women Over 40
| Test | Why It Matters After 40 |
|---|---|
| Oestradiol (E2) | Falling oestrogen is the driver of hot flushes, sleep disruption, mood changes, and brain fog. Baseline helps track the perimenopausal transition. |
| FSH + LH | Elevated FSH signals that the ovaries are working harder — a marker of perimenopause. LH:FSH ratio is informative for PCOS assessment. |
| AMH (Anti-Müllerian Hormone) | Ovarian reserve. Useful if fertility is still a consideration, or to understand where you are in the perimenopausal transition. |
| Total + free testosterone | Women need testosterone too. Low levels cause fatigue, low libido, and poor motivation. Often missed entirely. |
| Ferritin | Women with heavy periods — common in perimenopause — lose significant iron. Ferritin is the most sensitive marker and is often missed. |
| Thyroid (TSH + free T4 + TPO antibodies) | Autoimmune thyroid disease peaks in women in their 40s. TPO antibodies identify it before TSH becomes abnormal. |
| Vitamin D | Critical for bone density protection as oestrogen declines. Also linked to mood, fatigue, and immune function. |
| HbA1c + fasting glucose | Insulin sensitivity declines with falling oestrogen. Type 2 diabetes risk rises from the mid-40s onwards. |
| Lipid profile (full) | LDL rises after oestrogen declines. A full panel — including HDL, triglycerides, and ApoB — gives a complete cardiovascular picture. |
| B12 + folate | Deficiency worsens with age, especially if dietary intake is low or gut absorption has declined. |
| CRP (high-sensitivity) | Cardiovascular and inflammatory marker. Becomes increasingly relevant as metabolic risk rises. |
| Cortisol (morning) | Chronically elevated in women managing high workload, poor sleep, and hormonal flux simultaneously. |
Interpreting Your Hormones in the Right Context
Hormone levels fluctuate significantly across the menstrual cycle and are particularly erratic in perimenopause. A single oestradiol reading can be misleading. When assessing symptoms, your GP will consider the full clinical picture — symptoms, cycle history, sleep, mood — alongside the numbers.
Iron Deficiency After 40
Perimenopause often brings heavier, more irregular periods — which increases iron loss significantly. At the same time, GI absorption can decline with age. The result is iron deficiency that isn't reflected in haemoglobin until stores are severely depleted. If ferritin is below 30 µg/L, supplementation or IV iron should be considered.
Women's Health Blood Test in Surbiton
Our comprehensive panel for women over 40 covers hormones, thyroid, iron, cardiovascular risk, and metabolic health — with GP review and clear next steps.
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