A scan has shown a cyst or a fibroid

A cyst is a fluid-filled sac on an ovary, and the ordinary kind is the follicle that grows every month to release an egg, or the shell it leaves behind. Those are called functional cysts. They are found on scans all the time, they are gone within six to eight weeks, and they need a repeat scan, not an operation. The kinds that are watched more closely are a chocolate cyst, which is endometriosis inside the ovary; a dermoid, which is present from birth and grows slowly; and a cyst that is large, solid in parts, or found after menopause. Each has its own answer and none of them is an emergency on the day of the scan.

A fibroid is a firm lump of muscle in the wall of the uterus. They are very common, they are not cancer, and most women who have one never know. A fibroid matters because of three things only: how big it is, where it sits, and what it is doing to you. One that bulges into the cavity of the uterus can cause heavy periods or trouble conceiving even when it is small. One in the outer wall can be the size of an orange and cause nothing.

Endometriosis is tissue like the lining of the uterus growing where it should not, on the ovaries, the tubes, the ligaments behind the uterus, sometimes the bowel or bladder. It bleeds a little every month with nowhere to go, which is why it hurts: painful periods that have got worse over the years, pain deep inside with intercourse, pain with the bowels around the period, and for some women, difficulty conceiving. A scan can show a chocolate cyst or a thickened ligament; it cannot show the small deposits, so the story carries as much weight as the picture.

Bring the report and the images, and every earlier scan you have, because the most useful thing about a cyst is whether it has changed since last time. The story first: what brought you to the scan, how your periods run, whether there is pain and where, whether you are trying to conceive now or later. Then an examination, and a repeat scan where the old one is unclear, is more than a few weeks old, or was done for a different reason.

What comes out of the visit is a sorting: what is watched, with a date for the next scan; what is treated with medicine; and what genuinely needs a laparoscopy, which is a shorter list than the one you may have arrived with. If you are trying to conceive, that is addressed in the same conversation, because it is usually the question underneath the question.

• Time, for a functional cyst. A scan in six to eight weeks, timed after a period. Most are gone. Nothing else is needed.
• A blood test where the cyst is not the simple kind, to help tell the harmless varieties from the rare ones that are not, before any decision.
• Medicine first for endometriosis. Hormonal treatment that quietens the tissue, a pill or a progesterone or the device placed inside the uterus, with anti-inflammatory tablets for the pain. For many women this is the whole treatment for years.
• Watching a fibroid that is not causing symptoms, with a scan every year or two. Fibroids grow slowly, and they shrink after menopause.
• Treating the symptom, not the lump. Heavy periods from a fibroid are often controlled with the tablets and devices on the heavy periods page without touching the fibroid at all.
• A fertility plan alongside, where that is the real question: a fibroid inside the cavity is removed before trying further, one in the wall is often left alone, and endometriosis changes the timing of the steps on the fertility page rather than ruling anything out.

The cyst was found by chance. Do nothing this week. Book a repeat scan for six to eight weeks from now, just after a period, and come with both reports. The great majority of cysts found by chance are gone by then.

You were told to operate this month. Ask why this month. A cyst that is very large, has twisted, or has features that need a closer look is a reason; a functional cyst is not. Bring the report for a second opinion before the date, not after it. A consultation is allowed to agree with the first doctor, and it is allowed not to.

You are trying to conceive and have a fibroid. Where it is matters more than how big it is. A fibroid that pushes into the cavity is removed before further fertility treatment; one in the wall or on the outside is usually left, and trying continues. The scan tells which, and so does the visit.

• Sudden severe pain on one side, especially with vomiting or faintness: the same day
• A cyst larger than five centimetres on the report, or one described as complex or solid
• Any cyst found after menopause
• Bloating or fullness that has come on over weeks and does not go
• Heavy bleeding with a known fibroid and symptoms of anaemia
• Trying to conceive for six months with a known cyst, fibroid or endometriosis

A laparoscopy is keyhole surgery: three or four small cuts, a camera, and a stay of a day or two. It removes a cyst while keeping the ovary, removes a fibroid while keeping the uterus, and treats endometriosis by removing or burning the deposits. A hysteroscopy is a telescope through the cervix with no cut at all, for a polyp or a fibroid inside the cavity. Before either is booked you are told what is planned, what the alternatives are, what could go wrong, and what would happen if you waited. You are told who will do it and where, before anything is booked.