Short answer: The NHS says period blood is often red when flow is heaviest and may be pink or brown on lighter days. Color alone does not identify a condition or show whether a cycle is healthy.

What the NHS describes

A period is blood and womb lining leaving the body over several days. NHS guidance says bleeding tends to be heaviest in the first two days; the blood may be red then and pink or brown on lighter days.

That means more than one color can appear within an ordinary period. A change from red to brown near a lighter part of the bleed is not, by itself, a diagnosis.

What is more useful to track

Color is subjective and can look different with lighting, products and flow. A more useful record describes when the bleeding occurred and how the overall pattern changed.

If you are preparing for an appointment, focus on cycle dates, total bleeding days, product-change frequency, leaks, clots, pain and daily-life impact.

  • Was the bleeding during an expected period or between periods?
  • Was flow lighter or heavier than usual?
  • How many days did it last?
  • Were there new pain, dizziness, tiredness or other symptoms?
  • Did the pattern repeat?

When color is not the decision

Do not use a color chart to diagnose infection, pregnancy, miscarriage or another cause. NHS guidance recommends checking bleeding between periods, after sex or after menopause regardless of color.

For heavy periods, practical signs such as changing protection every one to two hours, bleeding longer than seven days, large clots, leaks and life impact matter more than whether the blood looks bright or dark.

If you save a color note, place it beside those higher-value details. A note such as 'brown spotting two days after the period ended, repeated for three cycles' communicates timing and recurrence. 'Brown blood' alone does not give a clinician the same context or identify why it happened. The pattern, not a shade chart, should guide the decision to seek advice.

Important: A photo or color description cannot diagnose the cause of bleeding. Unexpected bleeding or a meaningful change in pattern should be discussed with a qualified clinician.

Sources

  • NHS: Periods overview — Reviewed 5 January 2023; describes normal color changes across heavier and lighter days.
  • NHS: Heavy periods — Reviewed 19 September 2024; lists pattern and impact signs that matter clinically.