Magnesium blood test in Chiswick

What the test measures

Magnesium is a mineral involved in hundreds of chemical reactions. It helps muscles and nerves work, supports a steady heart rhythm and helps keep calcium and potassium in balance. Most of it is stored in bone and inside cells, with only a small share in the blood.

This test measures serum magnesium. Because the blood level is held within a fairly narrow band, a normal result does not always mean body stores are full, but a low result is a useful sign that intake, absorption or losses need a closer look. Magnesium is often read with calcium, potassium and kidney markers, as these are closely linked.

Your price includes the sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result and a GP feedback report on request. No GP referral is needed.

Who it is for

• You follow a restrictive or highly processed diet and want to check your mineral intake is adequate.
• You have muscle cramps, twitching or tiredness and would like to rule in or out a simple cause.
• You take medicines linked with low magnesium, such as long-term proton pump inhibitors for acid reflux or some diuretics.
• You have a digestive condition, ongoing diarrhoea or a history of heavy alcohol use.
• Your GP has found low calcium or potassium and suggested checking magnesium too.

Understanding your result

A low level can follow poor intake, reduced absorption, losses through the kidneys or bowel, alcohol, or medicines such as proton pump inhibitors and diuretics, and it can make low potassium or calcium harder to correct. A raised level is less common and is usually linked to reduced kidney function or taking large amounts of magnesium in supplements, antacids or laxatives.

Your report shows the laboratory reference range, and your practitioner will read your result alongside your diet, symptoms and medicines. A value outside the range is a starting point for discussion rather than a diagnosis.

Preparing for your test

No fasting is needed for a magnesium test. Keep taking prescribed medicines as normal, but tell us about them when you book. If you take a magnesium supplement, mention it, and you may be asked to leave it out on the morning of the test so the result reflects your usual level rather than a recent dose. Drink water as usual beforehand.

Magnesium sits alongside related markers in several checks. The Tired All The Time check looks at magnesium with iron, thyroid and vitamin markers, and the Nutritional and Digestive Health check is designed for diet and absorption questions. You can also see every blood test and price in Chiswick.

Questions

How much is a magnesium blood test in Chiswick?

A magnesium blood test costs £39. This includes the sample at our clinic, analysis at an accredited laboratory, a practitioner review and a GP feedback report on request.

Can a normal blood magnesium still mean I am low?

It can. The body keeps the blood level steady by drawing on bone and cell stores, so a normal result does not fully rule out low total stores.

Should I start a magnesium supplement if my result is low?

Talk it through first. The cause of a low level matters, and supplements are not suitable for everyone, particularly people with reduced kidney function.

How often should magnesium be checked?

A single check is usually enough, unless your result is low or you take a medicine that affects magnesium.