Hypocalcaemia

Key facts

• Hypocalcaemia means blood calcium has fallen below the normal range; calcium controls how nerves fire and muscles contract, so even a modest drop causes symptoms.
• Early signs include tingling or numbness around the lips and fingertips, muscle cramps and unusual fatigue; more severe cases bring muscle twitching (tetany) or spasms.
• Common causes are underactive parathyroid glands (often after thyroid surgery), vitamin D deficiency, and kidney disease that blocks the body's ability to activate vitamin D.
• Treatment centres on active vitamin D medicines such as calcitriol and alfacalcidol, which restore calcium absorption from food.

What low calcium feels like

Early signs are easy to miss. Tingling or numbness around the lips and in the fingertips, muscle cramps, or an unusual feeling of fatigue are the most common complaints. In more pronounced cases people notice muscle twitching (tetany) or spasms. A sudden jolt-like spasm, a change in heartbeat, or a seizure needs urgent medical attention.

Why it happens and how it's treated

The most frequent causes are underactive parathyroid glands (often after thyroid surgery), vitamin D deficiency, and kidney disease that impairs the body's ability to convert vitamin D into its active form. Because active vitamin D drives calcium absorption from food, treatment focuses there. Medicines such as calcitriol and alfacalcidol are synthetic forms of active vitamin D used to restore calcium levels when the body cannot produce enough on its own. Both sit within the broader bone support category.

When to see a doctor

Get medical attention promptly for muscle twitching, a sudden spasm, a change in heartbeat, or a seizure. Persistent tingling, cramps or fatigue are also worth a checkup, since the underlying cause needs treating, not just the calcium level itself.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.