A 2017 study involving over 50,000 postmenopausal women found people are more likely to go through early and premature menopause if they started their period before their 12th birthday. Just over three percent of people who had their first period at 11 or younger had premature menopause compared to 1.8 percent of people whose first period occurred at the age of 13.

In fact, periods are often the main symptom — namely "if your periods become irregular or if they just stop altogether without any reason behind it," says Dr. Daniel Atkinson, clinical lead at online healthcare service Treated. Other menstrual signs include heavy bleeding and spotting, notes Healthline.

"You should keep track of your menstrual cycle to help determine this, as well as any changes to your skin and hair or if you’re gaining weight," adds Dr. Atkinson. And be aware of the other symptoms which include trouble sleeping, anxiety, vaginal dryness, hot flushes, memory or concentration problems, and reduced libido.

Menopausal symptoms "can start months, and in some cases years, before periods stop, and can last for up to four years after your last period," notes Dr. Venkat. "What’s key to remember is that everyone is different and there are no hard and fast rules."

"Early menopause can happen naturally if a [person's] ovaries stop making normal levels of certain hormones, particularly the hormone oestrogen," states the NHS. Known as premature ovarian failure or primary ovarian insufficiency (POI), the condition can also be caused by other factors.

"POI may be caused by autoimmune diseases (like rheumatoid arthritis) and chromosome abnormalities (like Turner syndrome) as well as radiotherapy and chemotherapy to treat cancer," says Dr. Atkinson, adding: "POI can be temporary or permanent when treating cancer, and your likelihood of experiencing it can be linked to your age and the type of treatment you are given."

Infections like tuberculosis, mumps, and malaria can also result in POI. So can "having your ovaries surgically removed before the age of 40," Dr. Atkinson notes. "This may be due to reasons such as ovarian cysts, endometriosis, or ovarian cancer." Unfortunately, like many things, the cause is often unknown.

Lifestyle factors can contribute to early menopause too, he says. "Smokers are more likely to reach menopause, and their symptoms can be more severe. Being below a healthy weight can be a factor too, as oestrogen is stored in fatty tissue."

The cause of early menopause can be genetic. "It’s important to know if any other women in your family have been affected," Dr. Atkinson states. In some cases, per Healthline, you can predict when you are likely to start the menopause by identifying when your mum started hers. But it's not always inherited.

As Healthline explains, oestrogen has a particularly important role in the body. It amps up good cholesterol and reduces the bad type, and also helps stop bones from thinning. So when you have a lack of the hormone for a lengthy period of time, you can be more likely to experience osteoporosis and cardiovascular disease along with dementia and depression.

"Women under 40 who experience premature menopause were nearly twice as likely to have a non-fatal cardiovascular event before the age of 60," Professor Gita Mishra told Science Daily in relation to a recent study carried out by the University of Queensland. These events included heart attacks and strokes.

Early menopause can, however, have certain benefits, per Healthline, including protecting against estrogen-sensitive cancers.

Although no treatment is required for early menopause, it can be helpful to supply the body with the oestrogen it would normally make. Plus, it can relieve any symptoms that are detrimentally impacting your life.

The main two options, states the NHS, are the combined contraceptive pill or HRT. But it is advisable to speak to your GP about the best course of action. They can also explain any potential side effects and risks of taking such medication. If your mental health has been affected, you may also want to see a therapist for coping methods and general support.

Although there have been some reports of pregnancies in people with premature menopause, this is a rare occurrence, states an article in the Annals of Medical and Health Science Research. You may still be able to have children via IVF and egg donation or you could explore the routes of surrogacy or adoption, notes the NHS.

A number of support networks exist for those experiencing early or premature menopause, including Daisy Network, Menopause Matters, and Fertility Friends.

"Please do not struggle alone or feel ashamed or embarrassed by what is happening to you and your body," says Dr. Venkat. "Menopause happens to all women so communication needs to be open and the conversation alive."