Ovaries

The ovaries are two small, oval-shaped organs that sit on either side of the uterus. They have two main jobs: storing and releasing eggs, and producing the hormones oestrogen and progesterone. They're a key part of the reproductive system and they're what drives the menstrual cycle.

• The ovaries store eggs and release one roughly once a month (ovulation).
• They produce oestrogen and progesterone — the hormones that control the menstrual cycle and drive puberty.
• You're born with all the eggs you'll ever have — roughly 1-2 million, though most are reabsorbed before puberty.
• Each ovary is about the size of an almond or a large grape.
• If one ovary is removed or stops working, the other can usually take over.

[DIAGRAM: Labelled diagram of female reproductive system with ovaries highlighted, showing position relative to fallopian tubes and uterus]

What they do

The ovaries sit at the ends of the fallopian tubes, one on each side of the uterus. Each month, hormones from the brain (FSH and LH) signal the ovaries to mature a batch of eggs. Usually only one egg becomes dominant and is released — this is ovulation. The egg leaves the ovary and enters the fallopian tube, where it can potentially be fertilised by sperm.

At the same time, the ovaries produce hormones. Oestrogen rises in the first half of the cycle, driving the uterus lining to thicken. After ovulation, the empty follicle (where the egg came from) produces progesterone, which maintains the lining. If no pregnancy happens, both hormones drop and you get a period.

The egg supply

Unlike testes, which continuously produce new sperm from puberty onwards, ovaries don't make new eggs. You're born with your entire supply. By birth there are about 1-2 million immature eggs. By puberty, that's dropped to around 300,000-400,000. Over a lifetime, only about 400-500 will ever be released through ovulation. The rest are gradually reabsorbed by the body.

This is why fertility naturally declines with age — not just because of fewer eggs, but because egg quality also decreases over time. For young people, this isn't something to worry about right now.

Ovarian pain

It's possible to feel a twinge or dull ache from your ovaries around ovulation — a sensation called mittelschmerz. This usually affects one side (whichever ovary released the egg that month) and is harmless.

Ovarian cysts — small fluid-filled sacs on or in the ovary — are fairly common and usually harmless, often disappearing on their own. Occasionally they can cause pain if they grow large or twist. Conditions like PCOS (polycystic ovary syndrome) involve the ovaries and can affect periods, hormones, and fertility — it's worth knowing about but not worth panicking over if you have irregular periods, since irregular cycles are very common in the first few years. [CHECK: PCOS prevalence in young people]

Things people get wrong

"You ovulate from the same ovary every month." Not necessarily. Ovulation can alternate between ovaries, but it doesn't always follow a strict pattern. Sometimes the same ovary ovulates several months in a row.

"If you lose one ovary, you can't get pregnant." Usually you can. If one ovary is removed (due to a cyst, torsion, or other issue), the remaining one typically compensates and continues to ovulate and produce hormones.

"The ovaries are deep inside the body and you can never feel them." Most of the time you can't, but during ovulation some people feel a noticeable twinge. And certain conditions (like large cysts) can cause real pain.

Things people ask about ovaries

Where exactly are the ovaries?

They sit in the lower abdomen, one on each side of the uterus, roughly at hip level. You can't feel them from the outside, but a doctor can sometimes feel them during an internal examination.

What is PCOS?

Polycystic ovary syndrome is a condition where the ovaries produce higher-than-usual levels of certain hormones, which can affect ovulation, periods, and other things like skin and hair. It's quite common and manageable with the right support, but it needs a GP to diagnose and help manage.

Do the ovaries ever stop working?

Eventually, yes — this is menopause, when the ovaries run low on eggs and stop producing as much oestrogen and progesterone. Periods stop and fertility ends. This usually happens in the late 40s or 50s. Very rarely, it can happen earlier (premature ovarian insufficiency).

Where to get help

• Your GP — for any concerns about pelvic pain, irregular periods, or suspected PCOS.
• NHS 111 — if you have sudden, severe pain on one side of your lower abdomen (could be an ovarian cyst or torsion — needs checking).

The ovaries are two small organs inside the body, about the size of large grapes. There's one on each side of the womb. They have two main jobs.

The first job is storing and releasing eggs. Girls and women are born with all the eggs they'll ever have. About once a month, one egg is released from one of the ovaries. This is called ovulation. The egg travels along a tube towards the womb, where it can meet a sperm and start a pregnancy.

The second job is making hormones. The ovaries make the hormones that cause the changes during puberty — like breasts developing, hips getting wider, and periods starting. They also control the monthly cycle by making hormone levels rise and fall.

Sometimes you can feel a small twinge of pain from an ovary around the time an egg is released. This is normal and usually goes away quickly.

If one ovary has to be removed for any reason, the other one can usually keep doing the job on its own.

The ovaries slowly run out of eggs over many years. When they stop releasing eggs and making as much hormone, periods stop. This is called menopause, and it usually happens in the late 40s or 50s.