Is a grey period blood clot normal?

A single greyish clot during a normal period isn't always a problem, but grey tissue is worth mentioning to a provider, especially with a bad smell. If you're pregnant or could be, passing grey or white lumps with bleeding can be a sign of miscarriage, so call your provider the same day.

What color is stress period blood?

Stress doesn't have a period blood colour. Stress can delay a period, and a slower, later flow can look darker or browner. Grey is not a stress colour: grey discharge usually points to bacterial vaginosis and is worth getting checked.

What is a grey period?

A period that looks grey or has greyish discharge mixed in is most often caused by bacterial vaginosis, especially with a fishy smell. It isn't a normal period colour. See a doctor or sexual health clinic for a quick check and treatment.

Grey Period Blood

Grey isn't a normal colour for period blood, so it's the one most worth getting checked. Grey or greyish-white discharge, especially if it's thin and watery with a strong fishy smell, is a common sign of bacterial vaginosis (BV). BV is an imbalance of vaginal bacteria, not an STI, and it's easily treated. Grey can also matter in pregnancy: passing grey or white lumps with bleeding can be a sign of miscarriage and needs a same-day call. This page explains what grey period blood or discharge usually means, what a grey clot can be, what to do if you're pregnant, and how BV is treated.

grey blood — worth a check

Unlike brown or black, grey isn't just “old blood” — it's the colour most worth getting checked.

What grey period blood means

Grey is the period-blood colour worth paying real attention to. Grey discharge, or grey-tinged bleeding, especially when it comes with a strong or fishy odour, itching, or irritation, can be a sign of bacterial vaginosis — a common imbalance of vaginal bacteria that is easily treated once identified. In someone who is pregnant, passing grey tissue or discharge can signal a problem and should be checked promptly. Unlike the brown-to-black range, grey doesn't fit the simple “old blood” explanation, which is why it's the one colour that more often warrants a conversation with a healthcare provider rather than a shrug.

When you’ll usually see it

Alongside a strong or fishy odour
With itching or irritation
During pregnancy (needs prompt review)

Want to see when colours like this show up for you? Our free private tracker lets you log your flow and add a short note each day, so patterns are easier to spot.

Why is my period discharge grey?

The most common reason is bacterial vaginosis. BV often causes thin, watery, greyish-white discharge with a strong fishy smell, particularly after sex. It can mix with period blood and make it look grey or dull. Most people with BV have no other symptoms, and some have none at all.

BV is treated with antibiotics from a doctor or sexual health clinic. It isn't an STI, although sex can trigger it.

Grey lumps or clots in pregnancy

If you're pregnant, or could be, and you pass pink, grey or white lumps from your vagina, with or without bleeding and cramps, contact your provider or maternity unit the same day, as it can be a sign of miscarriage. Get urgent help for severe tummy pain, shoulder pain, feeling faint, or bleeding that soaks a pad soon after you put it on.

BV in pregnancy is usually harmless, but there is a small chance of complications, so it's worth getting treated if you have symptoms.

When to see a provider

See a provider if you notice grey discharge — particularly with an odour, itching, or irritation — and seek prompt review if you're pregnant and pass grey discharge or tissue.

Grey period blood: your questions

Is grey period blood normal?: Unlike brown or black, grey isn't just “old blood” — it's the colour most worth getting checked. See a provider if you notice grey discharge — particularly with an odour, itching, or irritation — and seek prompt review if you're pregnant and pass grey discharge or tissue.
Is a grey period blood clot normal?: A single greyish clot during a normal period isn't always a problem, but grey tissue is worth mentioning to a provider, especially with a bad smell. If you're pregnant or could be, passing grey or white lumps with bleeding can be a sign of miscarriage, so call your provider the same day.
What color is stress period blood?: Stress doesn't have a period blood colour. Stress can delay a period, and a slower, later flow can look darker or browner. Grey is not a stress colour: grey discharge usually points to bacterial vaginosis and is worth getting checked.
What is a grey period?: A period that looks grey or has greyish discharge mixed in is most often caused by bacterial vaginosis, especially with a fishy smell. It isn't a normal period colour. See a doctor or sexual health clinic for a quick check and treatment.

Related guides

Grey discharge — the full guide to BV and grey discharge
Why period blood smells — fishy smells and what they mean
Pregnancy discharge by trimester — what to tell your midwife about
White discharge — how normal discharge compares
Period blood colour chart — every colour side by side

Other period blood colours

← All period blood colours: the full guide

Sources

Checked against the following public guidance on October 2, 2026. Advice can differ between countries; your doctor, nurse or midwife can apply it to you.