Some people experience nausea just before they get their period. This is common and is not usually a cause for concern.
Nausea before a period could be caused by many factors, including cramps, premenstrual syndrome (PMS), and pregnancy. If symptoms are severe, this could indicate an underlying condition such as endometriosis.
PMS is the main cause of nausea before a period. Around 20 to 50 percent of women experience PMS in the 7 to 10 days before their period.
Read on to learn about possible causes and treatments for nausea before a period.
Nausea before a period is common. What matters most, however, is what is normal for the individual.
Feeling nauseated before a period may be a regular symptom for some people. However, a sudden change in PMS symptoms can indicate an underlying medical problem.
A person should also see a doctor if they are:
- experiencing this symptom for the first time
- unable to keep down any food
- losing weight due to frequent vomiting
- feeling dehydrated
- experiencing vomiting that gets worse over several days
Nausea before a period is often caused by PMS. However, there are some other possible causes, so it is wise to speak to a doctor if the symptoms are unusual or interfering with everyday activities.
Premenstural syndrome (PMS)
Researchers are still unsure about what causes PMS, and why some people experience it and others do not.
Possible explanations for PMS include:
- Serotonin levels. Serotonin is a brain chemical linked to mood. There is some evidence that serotonin levels are lower before periods begin. Low serotonin can cause depression, anxiety, and other symptoms.
- Nutritional deficiencies. Not eating enough calcium or magnesium may make PMS worse.
- Endocrine disorders. The endocrine system regulates hormone levels. Problems with it due to diabetes, thyroid disease, polycystic ovarian syndrome (PCOS), or other diseases may make PMS worse.
- Hormonal shifts. Estrogen and progesterone are highest after ovulation because these hormones play key roles in pregnancy. When a period begins, estrogen and progesterone levels fall. Women with PMS typically experience nausea either right before a period or right after it starts.
- Genetics. While doctors have not identified specific genes linked to PMS, it seems to run in families.
Hormones are the body’s chemical messengers, so changes in hormone levels can affect how it responds to many experiences.
A 2018 study of women undergoing breast cancer surgery under general anesthesia, found a link between menstruation and vomiting. Women were much more likely to experience vomiting after surgery when they were getting their periods.
Premenstrual dysphoric disorder
Premenstrual dysphoric disorder (PMDD) is a severe form of PMS. People with PMDD typically also have serious mood swings and may have depression and anxiety.
Endometriosis is when tissue similar to the tissue that lines the uterus develops outside of it, sticking to other organs, such as the ovaries and fallopian tubes.
Some women with endometriosis do not have symptoms. For others, endometriosis can be debilitating, causing intense pain and heavy bleeding during a period and even throughout the month. Endometriosis is also a leading cause of infertility.
One study found higher rates of stomach and digestive problems in women with endometriosis. Around 85 percent of women with endometriosis reported gastrointestinal problems during the previous year.
In addition to nausea, they also reported gas, bloating, diarrhea, stomach pain, and constipation.
Nausea and vomiting are among the earliest signs of pregnancy. These symptoms may appear even before a woman misses her period.
Shortly after a fertilized egg implants itself in the uterus, a woman’s body begins producing human chorionic gonadotropin hormone (HCG).
HCG may play a role in morning sickness. It is also how most home pregnancy tests detect pregnancy.
Illness or infection
Not all symptoms that happen during a period are due to menstruation. Food poisoning, stomach viruses, food sensitivities, and a range of other health issues may cause nausea around the time of a period.
People experiencing nausea before their period for the first time, especially if it is severe or accompanied by vomiting or intense stomach pain, may have an unrelated illness or infection.
Anyone experiencing frequent nausea before their period should talk to a doctor about possible underlying causes. The treatment they recommend will depend on what is responsible for nausea.
Some strategies that may help reduce mild nausea include:
- taking anti-nausea medication, such as Gravol or Pepto-Bismol
- monitoring food intake with a food diary to check for anything that might trigger nausea near a period
If nausea before a period is caused by an underlying medical condition, a doctor may recommend:
- birth control pills, which can help regulate hormones and are sometimes prescribed for endometriosis, PMDD, and PMS
- surgery to remove endometrial tissue that is outside of the uterus
- antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), which can help regulate serotonin levels and reduce symptoms of PMDD and PMS
Nausea is a common premenstrual symptom. For most people with nausea before a period, the symptoms can be managed with over-the-counter medications and by avoiding any trigger foods.
However, if nausea does not improve with conservative methods or if it is interfering with daily life, a person should speak to a doctor who specializes in menstrual health and work with them to come up with a treatment plan.