Your menstrual cycle can tell you a lot about your health. Regular periods between puberty and menopause mean your body is working normally. Period problems like irregular or painful periods may be a sign of a serious health problem. Period problems may also lead to other health problems, including problems getting pregnant. As your body transitions to older age and menopause, your changing hormone levels may increase or decrease your risk for chronic diseases.

Throughout your cycle, your hormones, which control your menstrual cycle, can also affect other aspects of your health — emotionally, mentally, and physically.

In the first half of your cycle (weeks one and two after your period starts during a typical 28-day cycle)

• Your energy levels might be higher.
• Your memory may be better, and your pain tolerance may be higher during these weeks. After your period ends is a good time to schedule a Pap test, as your cervical fluid is thinnest during this week, which can help show the clearest results.

In the second half of your cycle (beginning with ovulation)

• You may feel sluggish or forgetful.
• If you have a health problem, such as depression, irritable bowel syndrome, migraine, or asthma, your symptoms may get worse right before your period starts.
• If you have diabetes, you may find that your glucose levels are harder to control. Your glucose levels may be higher or lower than usual. This problem may be more common in women who also get premenstrual syndrome (PMS) symptoms.
• Levels of the brain chemical serotonin drop. Along with changing glucose levels, this can make you crave sugary and starchy foods.

Some period problems may lead to other health problems. Also, symptoms of other health problems might be worse or get better at certain times of your menstrual cycle.

These include:

• Anemia. Heavy bleeding is the most common cause of iron-deficiency anemia in women of childbearing age. Anemia is a condition that happens when your blood cannot carry enough oxygen to all of the different parts of your body because it does not have enough iron. This makes you pale or feel tired or weak.
• Asthma. Your asthma symptoms may be worse during some parts of your cycle.
• Depression. Women with a history of depression are more likely to have premenstrual syndrome (PMS) or premenstrual dysphoric disorder (PMDD). Symptoms of depression may also be worse before their period for women with depression.
• Diabetes. Women with irregular menstrual cycles, especially those longer than 40 days, have a higher risk for type 2 diabetes. Younger women between 18 and 22 with irregular periods are even more at risk. Polycystic ovary syndrome (PCOS) may be the link between irregular periods and diabetes. Most women with PCOS have problems with insulin and are at risk for type 2 diabetes.
• Heart disease and stroke. When you have amenorrhea or are in menopause, your ovaries may no longer make estrogen. Estrogen protects your body in many ways, including against heart disease and stroke.
• Osteoporosis. If you have amenorrhea, your bones might be at risk. Without estrogen from your ovaries, you lose bone mass, which puts you at risk for osteoporosis. Osteoporosis is a condition that causes your bones to become brittle and weak and break easily.
• Problems getting pregnant. Some conditions that cause period problems, such as endometriosis, uterine fibroids, or PCOS, can lead to infertility (problems getting pregnant).

Your weight can affect all aspects of your health, including your menstrual cycle.

If you are underweight, your body fat may drop so low that you stop ovulating, which could lead to irregular periods or no periods at all. Women with anorexia often have extreme weight loss below a healthy body weight. If you are not ovulating, your body is not producing normal levels of hormones like estrogen. A lack of estrogen between puberty and menopause can cause serious health problems.

If you are overweight, you are more likely than women of a healthy weight to have irregular periods or no periods at all. You may also have trouble getting pregnant. Your ovaries make the hormone estrogen. Fat cells also make estrogen. As you gain weight, your fat cells grow and release more estrogen. Too much estrogen can cause your body to react as if you are taking hormonal birth control (like the pill or vaginal ring) or are already pregnant. This can prevent you from ovulating and having a monthly period.

Not all period problems affect pregnancy. But some period problems can be a cause of infertility. Infertility means you are unable to get pregnant after one year of trying (or six months for women over 35).

• Irregular or missed periods may mean that you are not ovulating (your ovaries are not releasing an egg). Not ovulating is the most common cause of infertility in women.
• Painful, long, irregular, or heavy periods may be a sign that you could have problems getting pregnant. This depends on the cause of your period problem. For example, polycystic ovary syndrome (PCOS) is a common cause of heavy bleeding that affects fertility. Some women with uterine fibroids also have problems getting pregnant.

You may not be able to prevent problems in your menstrual cycle. Many period problems, such as heavy bleeding or painful periods, are caused by other problems with your reproductive system.

Your doctor can talk to you about treating heavy bleeding or painful periods with hormonal birth control methods, including intrauterine devices (IUDs), the pill, shot, or vaginal ring. If you are not trying to get pregnant, talk to your doctor about birth control. Hormonal birth control is sometimes prescribed by doctors for women’s health concerns other than preventing pregnancy.

Period cramps or pain is the most common period problem reported by women. Women who can control this pain with over-the-counter medicines like naproxen or ibuprofen may find that this medicine works best when started immediately before their period or as soon as their period starts.

Tracking your periods and menstrual cycle symptoms can also help your doctor or nurse understand your risk for health problems related to your period problem. Track when your period starts, how long it lasts, the amount of bleeding, and any pain you may have. Talk to your doctor or nurse about what is normal for you and any symptoms you have that are new or different.

Reaching a healthy weight and staying at a healthy weight and not smoking can also help improve period problems, including PMS symptoms, irregular periods, heavy bleeding, and sometimes period pain.