Cycle Science

Brown at the start, bright red on day two, near black first thing in the morning. Almost all of it comes down to one variable, and only two shades on the whole chart are actually saying something.

Heavy periods and constant exhaustion get filed as two separate facts about her. They are usually one. The mechanism, the test that a standard blood count misses, and what a partner can actually do about it.

Heavy periods, exhaustion, feeling cold, brain fog. Each gets its own explanation and nobody stacks them up. How a small gland in the neck rewrites a cycle, and the one cheap test that finds it.

Lining tissue growing inside the muscle of the uterus, present in maybe 20% to 35% of people, and invisible on a quick scan. What it does to a period, why it gets missed for years, and where a partner is genuinely useful.

In 40% to 80% of people with a uterus, and the most common reason a period turns punishing. What fibroids do to a cycle, the anemia nobody counts, and when to push for an appointment.

A one-sided ache a week after her period usually has an ordinary explanation. What ovulation pain is, how long it should last, and the handful of signs that mean stop guessing and call someone.

About 10% of reproductive-age women have it and diagnosis takes years. What endometriosis does, why it gets dismissed, and where a partner genuinely matters.

Cycles that skip months then arrive heavy. What PCOS does to her period, how the diagnosis actually works, and the four things a partner can do that help.

Light bleeding outside her period sounds alarming and usually is not. The common causes, the red flags that mean book a visit, and how to be the calm, useful one.

The bleed on the combined pill is a withdrawal bleed, not a period. What each method actually changes, what the mood evidence really says, and what is still trackable.