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Throwing Up On Period: Causes Of Vomiting First Day, Easy Treatment

By: Author Dr Akatakpo Dunn, MBBS, PG Dip Ultrasound, Prof Dip O&G (RCPI) Medical Director & Lead Obstetrician/Ultrasonologist, Verah Clinic & Maternity

Posted on Last updated:

Question: Why do I keep throwing up on period? Is vomiting first day of period sign of pregnancy?

There are many things a woman won’t take for granted, and PMS symptoms before period is one of them.

During this time, it’s common that some women get different signs, and sometimes, it’s possible symptoms will continue until after period starts. These are often called premenstrual syndrome (PMS) symptoms.

Days before the start of menstruation, most women get an on-off cramps and back pain. Depending on the severity of the cramps it could affect your regular routine.

Apart from cramps that some women experience, nausea before period is quite common, and the truth is, if you are unlucky, you may also experience vomiting. These symptoms can happen before your menstrual period and continue into your period. Doctors call painful periods “dysmenorrhea”, and nausea or vomiting can come together with the cramps in some women. Cleveland Clinic+1

If you are experiencing nausea and vomiting during period, you are not alone. Here’s an email I received from Amyla (one of my readers)

Dear Dr. Dunn, This is my very first time to visit this awesome blog. My hubby and I are just beginning to prepare for my second pregnancy this month. I had a crucial business trip last month, but before and after I returned, we had unprotected sexual intercourse.

I 100 % predicted to have got my menses yesterday, but its one day late and I feel odd signs. My breast seems heavier than usual, and I feel an uncontrollable urge to throw up.

Usually, I do experience nausea and vomiting before my period that continues to the first and second day of menstruation; But now, it’s worse, and it seems like I want to throw up every time.

I’ve had a pregnancy test done, but my hubby says its too early to confirm yet after a negative result. When can I take another pregnancy test, and is it possible it might not be pregnancy?

Apart from being a sign of period coming, nausea and vomiting could also be a sign of pregnancy. However, PMS and early pregnancy can feel very similar. So, if you are expecting your period, and then experience nausea, vomiting, heavy or sore breasts, back pain, and light vaginal bleeding, it could be pregnancy — especially if your period is late or much lighter than usual. In that case, it is better to do a home pregnancy test and repeat it a few days later if it is still negative and your period has not come. Mayo Clinic

Having said that, if you can’t hold food or water down and you are vomiting many times a day or for days, it may be something else. Severe vomiting can be due to pregnancy with very bad morning sickness, infections like food poisoning or stomach flu, stomach problems (gastritis, ulcers), or other medical conditions. Very rarely, serious illness can also cause vomiting. nhs.uk+1

This article explains why you are throwing up during period, other signs that may indicate you are already pregnant, and when to worry and see a doctor as quickly as possible.

Why I’m I throwing up on period?

If you are vomiting on period, Here are the possible reasons it happens.

High level of prostaglandins

Prostaglandins trigger many symptoms before and during period; And along with diarrhea or belly cramps, prostaglandins can act on your intestines and make you feel like throwing up. AAFP+3Mayo Clinic

After your ovaries release an egg (during ovulation), both estrogen and progesterone stimulate the lining covering your womb to become thickened.

This thick uterine lining, called endometrium, continues to increase in size throughout the latter part of your menstrual cycle. This happens because a woman’s body naturally prepares for pregnancy, and a thick endometrium help to house a fertilized egg (if you get pregnant).

In women that do not conceive, this endometrium is washed out as your period with bleeding for about 3–7 days.

Before your period starts, your body releases more prostaglandins, and it works to make your uterus muscles contract, and then expel the endometrium out of your womb. In women that have high levels of prostaglandins, they may experience different symptoms, including vomiting.

First of all, high levels of prostaglandins make your womb contract excessively, meaning, it causes pain that makes you have less appetite for food.

Also, prostaglandins can affect other body systems, including your digestive tract and intestines. If this happens, you will feel nausea, vomiting, and sometimes diarrhea or loose stool around your period.

Vomiting on period: When to worry?

Most time, women who experience vomiting during period will just have the usual cramps and may not have anything seriously wrong. In many women, hormone changes with high prostaglandins is the cause. Cleveland Clinic

Having said that, if you are throwing up all the time (many times a day, or for more than 24 hours), something is wrong. You must see a doctor quickly if:

  • You cannot keep any fluids down or you feel very weak, dizzy or like you will faint.

  • You have severe abdominal pain, pain on one side, or pain with fever.

  • Your vomit has blood or looks like coffee grounds.

  • You think you might be pregnant (missed period, very light “period”, or positive test).

Here are other reasons you can’t keep food in your stomach.

1. Endometriosis

If you are experiencing severe cramps and vomiting during period, it could be due to endometriosis, especially if the pain has been getting worse over many cycles.

Endometriosis is a common medical condition that affects young menstruating women, and involve the unusual displacement of your womb’s endometrium to other parts of your body.

It could be located in your oviducts (fallopian tubes), ovaries, or within your abdomen. To be frank, most women that have endometriosis mainly complain of unbearable cramps before and during menstruation. But some women also feel very nauseous and may want to throw up during period because the pain is so intense. Mayo Clinic+

Other symptoms of endometriosis are heavy vaginal bleeding that may last a long time or bleeding between periods. This means you now have much more sanitary pads or tampon than usual.

Also, you may feel nauseous, back pain, painful sexual intercourse, and body weakness.

You can read more here:

2. Uterine fibroids

If you are throwing up during period, it could be linked to uterine fibroids, especially if your periods are very heavy and painful.

Uterine fibroids are commonly found in a lot of women without any obvious symptoms. But if you are unlucky, you may experience prolonged periods, very heavy bleeding and strong cramps. This severe pain and blood loss can sometimes make you feel dizzy, weak, and want to throw up while menstruating. ACOG

Leg pain, constipation, and painful or frequent urination are other symptoms you may experience if fibroid tumor is very huge and pressing on nearby organs.

Helpful page:

3. Food poisoning

Very commonly, a lot of women will have nausea and vomiting because of toxic contaminated food or drinks they have taken hours or days back. This may just happen to fall at the same time as your period.

Food poisoning is quite common, and if you are experiencing vomiting for days after taking a meal, it could be due to bacterial, viral or parasitic infections.

Symptoms of food poisoning are low or high fever, diarrhea, nausea or vomiting, tummy cramps, body weakness, and lack of appetite. nhs.uk+1

If you have a high temperature, bloody stool, or cannot drink enough water, you should see a doctor or go to the emergency room.

Treatment of vomiting during period

If you feel like throwing up on period and it’s not serious, you could wait it out for a few days. Usually, after the first day or two of period, symptoms subside, and you will feel okay. Try small frequent sips of water, oral rehydration solution, ginger tea, and bland foods like crackers or toast as you can tolerate.

However, if you continue to feel nauseous or you are vomiting on period, here are easy ways to feel okay.

1. Birth control pills

Birth control medication (like the combined pill, patch, or some hormonal IUDs) can be used to reduce vomiting and pain during period. They work by controlling ovulation, thinning the lining of the womb, and lowering prostaglandins level that causes these symptoms. ACOG

They are not safe for everyone (for example if you smoke heavily, have migraine with aura, blood clots, or very high blood pressure), so always see your doctor or gynecologist for assistance before starting any hormonal birth control.

2. Use painkillers

Drugs like Ibuprofen and Naproxen can be used to help reduce your symptoms. They work by blocking the synthesis of prostaglandins, and if you’ve taken these medications before the start of period, you will notice symptoms will not be severe. Cleveland ClinicAlways take them with food, follow the dose on the pack, and avoid them if you have stomach ulcers, kidney disease, are pregnant (unless your doctor advises), or are allergic to them. If symptoms get worse, or you are still vomiting a lot, see a doctor for help. Your doctor may also prescribe anti-nausea medicines if you need them.

Vomiting first day of period, why?

If you are vomiting on the first day of period, it not unusual. This occurs because prostaglandins levels are most elevated on the first and second day of period, when the womb contracts strongly to push out the lining. Mayo Clinic

Provided you can drink fluids, pass urine regularly, and you don’t feel severely dizzy or weak, there is usually no reason to panic. Though, you must see your doctor if:

  • You are vomiting non-stop or cannot keep fluids down.

  • You have suddenly worse pain than your usual period pain.

  • You have fever, very heavy bleeding, or foul-smelling discharge.

  • You might be pregnant or have a positive pregnancy test.

Is vomiting during period a sign of pregnancy?

If you are throwing up while on period, its unlikely due to pregnancy if the bleeding is your usual flow and your pregnancy test is negative. In most women, vomiting during a normal period is from prostaglandins and painful cramps, not pregnancy.

However, implantation bleeding may be confused as period. Implantation bleeding is usually light spotting that happens around the time your period is due and is lighter than a normal period. If you also feel nauseous with vomiting, sore breasts, tiredness, and your “period” is much lighter or shorter than normal, its possible you are pregnant. Mayo Clinic+

For the most accurate results, most experts advise taking a home pregnancy test after the first day of a missed period, and repeating it a few days later if it is negative and your period still has not come. Mayo Clinic+

This guide explains what implantation bleeding looks like. If you have positive pregnancy test and you are vomiting with strong pain or heavy bleeding, you should see a doctor urgently to rule out miscarriage or ectopic pregnancy.