Nausea before your period: why you feel sick and what helps
Feeling sick just before or at the start of your period is common. Prostaglandins, the chemicals that trigger period cramps, also affect your gut and can cause nausea, and the drop in hormones before bleeding can upset digestion. It usually passes within a day or two of your period starting. Small bland meals, ginger, fluids and early pain relief help.
What period nausea feels like
It ranges from a vague queasy feeling and loss of appetite to actually being sick. For many people it comes packaged with other symptoms: cramps, headaches, dizziness, diarrhea or bloating. It tends to be worst on the day before or the first day of bleeding, when cramps peak.
- Queasiness, often worse in the morning or with an empty stomach
- Loss of appetite, or food smells putting you off
- Nausea that comes in waves with cramps
- Occasionally vomiting when pain is strong
- Feeling better once your period is properly underway
Why you feel sick before your period
Prostaglandins
As your period starts, the uterine lining releases prostaglandins to make the uterus contract. Some reach the bloodstream and the gut, where they affect muscle contractions and can cause nausea, vomiting and loose stools. People with stronger cramps often have more nausea, which is why treating the cramps often settles the stomach too.
Hormone shifts
Progesterone slows digestion in the luteal phase, which can leave you full, bloated and queasy. Then estrogen and progesterone fall sharply before your period, which can affect the gut and trigger headaches, another source of nausea.
Pain, headaches and anxiety
Strong pain on its own can make you feel sick. So can a menstrual migraine, and so can the anxiety many people feel before their period. They often overlap.
Period nausea or early pregnancy?
Nausea is a classic early pregnancy symptom, so if your period is late, it's natural to wonder. Pregnancy nausea usually starts around weeks 4 to 6 of pregnancy (counted from your last period) and continues, often with tender breasts, tiredness and needing to pee more. Period nausea lasts a day or two and fades once bleeding starts. The only way to know is a test from the day your period is due. See PMS vs pregnancy symptoms.
What helps nausea before your period
- Eat little and often. An empty stomach makes nausea worse. Try crackers, toast, rice, bananas or plain porridge every few hours.
- Try ginger. Ginger tea, ginger biscuits or capsules have reasonable evidence for nausea, and some small studies suggest ginger may ease period pain too.
- Sip fluids. Water, weak tea or flat ginger ale, especially if you've been sick.
- Treat cramps early. An NSAID such as ibuprofen or naproxen at the first sign of pain lowers prostaglandins. Take it with food to protect your stomach.
- Avoid strong triggers for a day or two: greasy or very spicy food, alcohol and strong smells.
- Get fresh air and rest. Lying with your head slightly raised can help.
- Ask about hormonal options if nausea is severe every month. Contraception that eases period pain often eases nausea too.
Crackers, ginger chews, a heat patch and your painkiller in your bag on the day your period is due can turn a miserable morning into a manageable one.
Nausea and how you feel
Feeling sick drains energy and patience, and it often coincides with the most emotionally tender days of the cycle. Not wanting to eat can also make mood dips worse. Knowing it's a predictable, short-lived part of your cycle helps. Plan a quiet first morning if you can. Read about mood during your period.
See a doctor if nausea or vomiting happens every period and affects daily life, if you can't keep fluids down, or if painkillers don't help your cramps. Get urgent help for vomiting with severe tummy pain, fever, signs of dehydration, or if you could be pregnant and have one-sided pain or bleeding. If you use tampons and get a sudden high fever, vomiting, diarrhea, dizziness and a sunburn-like rash, remove the tampon and get emergency care: this can be toxic shock syndrome.
Frequently asked questions
Is it normal to feel sick before your period?
Yes. Prostaglandins and hormone changes commonly cause nausea in the day or two before and the first day of your period.
Why do I throw up on my period?
High prostaglandin levels and strong pain can cause vomiting. Taking an anti-inflammatory early often helps. If it happens every month, see a doctor.
How can I tell period nausea from pregnancy nausea?
Period nausea fades once bleeding starts. Pregnancy nausea usually continues and comes with a missed period. A test is the only way to be sure.
What can I eat when I feel sick on my period?
Small amounts of bland food: crackers, toast, rice, bananas, soup or porridge, plus ginger and plenty of fluids.
Sources
- NHS: PMS (premenstrual syndrome)
- ACOG: Dysmenorrhea: Painful Periods
- Bernstein MT et al. Gastrointestinal symptoms before and during menses in healthy women. BMC Women's Health (2014)
- NHS: Toxic shock syndrome
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
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