For some women, menopause can be a welcome stage in their lives. Occurring around age 51 on average, menopause means that your periods have completely stopped for at least 12 months.

In total, menopause can last an average of seven years. Sometimes, it can occur for longer.

Aside from the absence of menstruation, menopause involves a whole host of effects on the body. Some of them can be uncomfortable (hello, hot flashes!), while others may go unnoticed.

Learn exactly how menopause can affect your body as well as some of the most common symptoms.

Estrogen and progesterone are the primary female hormones related to reproduction. When ovarian function declines with age, ovulation doesn’t occur regularly. This leads to irregular or missed periods.

Eventually, the ovaries stop ovulating altogether, and periods stop completely. This results in lower levels of estrogen and progesterone production by your ovaries.

You’ve officially entered menopause when you have 12 missed periods in a row. This natural life stage typically starts around your mid-40s to mid-50s and can last for several years.

While menopause means you won’t have any more periods and can no longer get pregnant, the decrease in estrogen also has several other effects on the body.

While your period may have been changing over the last several years during perimenopause, you don’t technically hit menopause until your monthly period has stopped completely. This means your body stops producing eggs for fertilization.

Without the shedding of an unfertilized egg every month, there’s no more menstruation.

Menopause can also affect other parts of the reproductive system. When you’re no longer going through monthly cycles, you may not have any thickening of cervical mucus toward the middle of your cycle, a symptom that often signifies ovulation.

Overall vaginal dryness and a lack of libido can also occur with menopause, but these don’t have to be permanent. An over-the-counter lubricant can help.

Your OB-GYN can also help you find other ways to increase your sex drive if you’re experiencing this effect from menopause.

The endocrine system includes the hormones responsible for reproduction. These include the hormones related to menopause, or in this case, a lack thereof: estrogen and progesterone.

Hot flashes are among the most talked about effects of menopause. These occur from a lack of estrogen. They can also last a few years after menopause.

Hot flashes cause feelings of sudden hotness, along with flushed skin and sweating. They can come on suddenly at any time of day or night. They can last just a few seconds or for several minutes at a time.

Lifestyle changes are extremely important in preventing and managing hot flashes. This can include avoiding caffeine and hot beverages.

Mindfulness techniques, such as meditation and hypnosis, may help alleviate hot flashes, too.

Menopause causes your body to reserve energy more, which means you won’t burn calories and fat as easily. This can lead to weight gain. Menopausal women are also more prone to gaining weight around their midline.

Menopause can affect your overall mood. You may feel happy and like yourself one day but then down the next.

You may also experience mood swings that cause irritability. It’s important to see your doctor if you continue to experience anxiety or depression beyond a couple of weeks. Menopause can be a trigger for depression.

Sleep can also be challenging during menopause. A drop in estrogen can cause hot flashes and night sweats that keep you up at night. These effects also make it difficult to fall asleep.

For unknown reasons, menopause is also said to affect memory. Memory loss is more common with age, but it’s unclear whether there’s a strict menopause connection or if another underlying cause may be at play here.

A drop in estrogen levels may also lead to bladder leakage, also called incontinence. You may find you urinate more often or you leak when you laugh, work out, or sneeze. Frequent urination can also interfere with your sleep.

Estrogens exert a cardioprotective effect on the body and lower levels of estrogen may increase the risk of cardiovascular disease. Lower levels of estrogen also affect the body’s cholesterol, which could increase the risk of heart attack or stroke. Your doctor may recommend hormone replacement therapy to counteract some of these changes.

Menopause causes your bones to lose their density. This can increase your risk of bone fractures. Menopausal women are also at a higher risk of developing osteoporosis.

A loss of muscle mass during menopause may also occur at a higher rate than before. Your joints may also become stiff and achy. Regular exercise can help reduce the loss of bone density and muscle mass. It may also reduce symptoms of joint pain.