Understanding menstruation

Menstruation, also known as a period, is the process in which a woman's body releases the lining of the uterus if pregnancy does not occur. This blood and tissue flow through the cervix and out the vagina.1 Read on to learn about the menstrual cycle, how to manage symptoms, healthy hygiene tips and more.

What’s the menstrual cycle?

The menstrual cycle is a woman’s monthly hormonal cycle that helps the body get ready for pregnancy. During this cycle, the lining of the uterus thickens to prepare for a fertilized egg. A woman’s period cycle can last anywhere from 24–38 days and can fluctuate each month.1

What are the 4 phases of the menstrual cycle?2

  1. Menstrual: The menstrual cycle starts each month with the menstrual phase. If an egg wasn’t fertilized the previous month, the body sheds that unfertilized egg and thick uterine lining (this becomes menstrual blood).
  2. Follicular: The follicular phase happens the same time as the one above. During this phase, your body releases a follicle stimulation hormone that starts egg production.
  3. Ovulation: The follicular phase ends when ovulation happens. This is when a mature egg gets released from your ovary and travels down the fallopian tube into your uterus. Your chances of getting pregnant are the highest during this phase of the menstrual cycle.
  4. Luteal: During this final phase, your body releases a hormone that keeps the uterine wall ready for implantation of a fertilized egg. If implantation doesn’t happen, hormones tell your body to shed the unfertilized egg and uterine lining.

What are symptoms during the menstrual cycle?

It’s common for some women to feel symptoms of their menstrual cycle, known as premenstrual syndrome (PMS). Some women may not have any PMS symptoms, while others may experience intense physical and emotional changes every month. Some of those symptoms may include:3

  • Anxiety, depressed mood or crying spells
  • Mood swings
  • Changes in appetite
  • Change in libido
  • Headache
  • Fatigue
  • Weight fluctuation
  • Breast tenderness
  • Constipation or diarrhea
  • Acne 

Tips for good hygiene

Proper feminine hygiene can help prevent unwanted odors, irritation or health conditions no matter where you are in your cycle. Tips for good feminine hygiene include things like:4

  • Wearing loose-fitting underwear and bottoms
  • Choosing unscented hygiene products
  • Removing or changing menstrual products (like tampons and pads) frequently throughout the day
  • Gently clean your genitals every day, and before and after sex
  • Drink plenty of liquids to prevent yeast infections

What menstrual products should I use?

There are lots of different brands on the market that sell menstrual products. You may select your product(s) of choice based on things like cost, materials and ease of use. You may also find certain products work well for certain times of day, certain activities (like swimming) or during certain stages of life. Commonly used menstrual products include:1,5

Pad: This absorbent material fit comfortably inside your underwear and catch period blood. You can choose the size of pad to match your flow — mini for light days and super for heavier days. Be sure to change them regularly to prevent buildup of bacteria, leaking and odor.

Tampon: This tube-shaped product is made from compressed absorbent material that gets inserted into the vagina to soak up period blood. You can buy tampons that come inside an applicator to make them easier to insert. All tampons have strings at the bottom to use when it’s time to pull them out. It’s important to use the right absorbency level for the amount of blood you’re losing. A dry tampon can irritate your vagina or lead to toxic shock syndrome (TSS). TSS is a rare — but serious — infection requiring emergency attention.6 Leaving a tampon in too long (like overnight) may also cause TSS, so change your tampon often. The CDC recommends tampons be changed every 4-8 hours.4

Menstrual cup: Similar to a tampon, a menstrual cup is a small, flexible cup that gets inserted into the vagina to catch period blood. A reusable menstrual cup is a good option if you want to save money on menstrual products. Just be sure to wash it according to its instructions.

Period underwear: Depending on how heavy your cycle is, period underwear could be an option too. They are machine washable underwear that have a pad like material sewn in to absorb the period blood.

When should I see a doctor about my period?

It’s important to check in with your doctor about your reproductive health during your yearly wellness visit with your primary care provider or obstetrician/gynecologist (OBGYN). If you’re experiencing severe PMS symptoms, unusual bleeding, or irregular or missed periods, schedule an appointment with your provider right away. They’ll help rule out other health conditions and offer recommendations for managing symptoms.7

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Frequently asked questions about menstruation