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What’s a healthy period?

A period, also known as menstruation, is a natural biological process experienced by women and girls during their reproductive years. Periods usually start between the ages of 11 and 14 and continue until menopause, which on average occurs between 45-55 years old. Getting your period can be an exciting milestone marking the transition from girlhood into womanhood. However, it also comes with physical and emotional changes that can cause discomfort or concern if you don’t know what to expect. Understanding what’s normal and healthy when it comes to your menstrual cycle will help you take care of your body and know when to seek medical advice.

What happens during the menstrual cycle?

The menstrual cycle is the process of ovulation and menstruation that occurs in women’s bodies to prepare for potential pregnancy each month. A cycle typically lasts between 21-35 days. Here are the main phases:

  • Follicular phase: This phase starts on the first day of your period. During the follicular phase, estrogen levels begin to rise and mature an egg in one of your ovaries. The uterine lining also starts to thicken.
  • Ovulation: Estrogen levels peak around day 14 of a 28-day cycle, triggering ovulation. This is when the mature egg is released from the ovary. The egg travels down the fallopian tube where it can potentially be fertilized before being shed during your period if conception does not occur.
  • Luteal phase: After ovulation, the egg that was released breaks down and your hormone levels change. Progesterone levels rise to thicken the uterine lining even more, preparing for potential implantation of a fertilized egg. PMS symptoms like breast tenderness and mood changes often occur during this phase.
  • Menstruation: If the egg is not fertilized, hormone levels drop around day 28 of a 28-day cycle. This signals your uterus to shed its lining, starting your period. The entire uterine wall breaks down and is shed through the vagina along with blood.

Cycle length and ovulation timing can vary each month. The average cycle length is 28 days, but can range from 21-35 days and still be considered normal. Ovulation typically occurs around day 14, but could happen anytime between days 10-21 depending on the length of your individual cycle.

What’s a normal period length and flow?

Periods can last anywhere from 3-7 days on average. The menstrual flow (amount of blood loss) also varies each month and from woman to woman. Here are some general guidelines for what’s considered normal period flow:

  • Light flow: Changing a pad or tampon every 3-4 hours. Little to no blood clots.
  • Moderate flow: Changing a pad or tampon every 2-3 hours. Some blood clots may be passed.
  • Heavy flow: Changing a pad or tampon about every 1-2 hours. Passing large blood clots.

Bleeding longer than 7 days or soaking through a pad or tampon in under 2 hours indicates an excessively heavy flow. The total blood loss over the entire period should not regularly exceed 80mL (about 6 tablespoons).

Typical period blood loss per cycle:

Flow Total blood loss per cycle
Light Less than 20mL
Moderate 20-60mL
Heavy 60-80mL

What’s a normal menstrual cycle length?

A normal menstrual cycle can range from 21-35 days from the start of one period to the beginning of the next. Cycles that are shorter than 21 days or longer than 35 days are considered irregular. Here is an overview of average cycle lengths:

  • Short cycles: 21-24 days
  • Average cycles: 28 days
  • Long cycles: 32-35 days

It’s also normal for cycle length to vary somewhat month-to-month or change over the years. For example, cycles tend to get shorter and more regular in the 18-35 age range. Once in your 40s, cycles may lengthen again as you approach menopause. Sudden or drastic changes in cycle length can indicate an underlying health condition.

Average menstrual cycle length by age:

Age range Usual cycle length
Younger teens 21-45 days
18-35 years old 28 days
Over 40 Shorter or longer than 28 days

What are normal vs. abnormal periods?

While there is quite a bit of variation in what’s considered normal when it comes to menstrual cycles, some signs could indicate a potential medical problem:

Normal period features:

  • Lasting 4-7 days
  • Occurring every 21-35 days
  • Producing a moderate blood flow
  • Causing mild to moderate cramping, bloating, backaches, or other discomfort around the time of your period

Abnormal period signs to look out for:

  • Bleeding that lasts over 7 days or produces very heavy flow
  • Menstruating more often than every 21 days or less often than every 35 days
  • Bleeding between periods
  • Severe pain that disrupts your daily activities or requires medication
  • Sudden changes in your cycle that persist over 3 months

Any of these abnormalities should prompt you to schedule an appointment with your doctor. They can help determine if an underlying health issue is causing the changes and if treatment is needed.

What affects your period?

Hormonal fluctuations are the main driver of menstrual cycles and period changes. But various other factors can impact your cycle length, flow, and associated symptoms as well. These include:

  • Age: Menarche (your first period) typically occurs between 11-14. Cycles become more regular through your 20s and 30s. Irregularity often increases again in perimenopause during your 40s as estrogen levels decline.
  • Birth control: Methods like the pill regulate hormone levels to control bleeding. This leads to lighter, predictable periods or no periods at all depending on the method.
  • Pregnancy and breastfeeding: Both cause hormonal changes that interrupt normal menstrual cycles.
  • Medical conditions: Thyroid disorders, endometriosis, PCOS, pelvic inflammatory disease, uterine fibroids, and other issues can impact cycle regularity and flow.
  • Eating disorders and rapid weight loss: Low body weight and nutritional deficiencies from conditions like anorexia can cause missed or irregular periods.
  • Stress: High stress is linked to longer, irregular cycles and heavier periods in some women.
  • Medications: Some drugs like birth control pills or antidepressants affect hormone levels that control menstruation.

When should you see a doctor?

Schedule an appointment with your doctor or gynecologist if your period suddenly changes or shows any of the following abnormal characteristics:

  • Bleeding longer than 7 days
  • Bleeding or spotting between periods
  • Soaking through a pad or tampon in under 2 hours (excessive flow)
  • Cycles consistently shorter than 21 days or longer than 35 days
  • No period for 3 months or more (amenorrhea)
  • Severe pelvic pain or cramping
  • Recurrent headaches, nausea, or breast tenderness a week before your period

Evaluation and testing can help identify potential causes like uterine polyps, endometriosis, hormone imbalances, or other medical conditions. Treatment is available to address abnormal bleeding, alleviate difficult symptoms, and regulate your cycle.

When is period irregularity normal?

Some variation in your cycle length and flow is to be expected. Here are some common times when irregular or missed periods can occur without being cause for concern:

  • Perimenopause: Changes begin up to 10 years before menopause as fertility declines. Longer, heavier, or more irregular cycles are common.
  • Post-miscarriage: It may take 4-6 weeks for normal menstrual cycles to resume after a pregnancy loss.
  • Breastfeeding: Lactation prevents ovulation so your period often doesn’t return for several months after childbirth.
  • Hormonal birth control: Methods like the pill lead to lighter, less frequent, or absent periods in some women.
  • Significant weight loss or gain: Quick weight changes of around 10-15% of your body weight can disrupt cycles.
  • Excessive exercise: High-intensity athletic training of over 5 hours a day causes missed or irregular periods in some female athletes.
  • Traveling: Time zone changes or disturbances in your sleep/diet routine can temporarily impact cycle regularity.
  • Starting periods: It’s normal to have very irregular cycle lengths the first 1-2 years after your first period.

However, if these situations do not explain your menstrual irregularities or you remain concerned, check in with your doctor.

How can you manage your symptoms?

Most women experience some discomfort around their periods. Here are some tips for alleviating common symptoms:

  • Cramps: Over-the-counter pain relievers like ibuprofen help relax the uterine muscles causing cramps. Heating pads applied to your abdomen bring relief too.
  • Sore breasts: Wear a supportive bra to lessen breast tenderness and sensitivity.
  • Bloating: Limit sodium and gas-producing foods before and during your period. Gentle cardio exercise can also provide relief.
  • Fatigue: Beating fatigue starts with getting enough sleep (7-9 hours per night) and maintaining an iron-rich diet to prevent deficiencies making fatigue worse.
  • Heavy flow: Use overnight pads or tampons with a higher absorbency to help manage heavy flow days.
  • Mood changes: Emotional self-care like taking time to relax, talking with understanding friends, or meditating can help stabilize mood swings.


Getting your first period can feel daunting, but it is a normal biological process that most women adjust to over time. While some pain, bloating, and irritability during your period is common, very heavy bleeding or severe discomfort is not. Being aware of what constitutes a healthy cycle length, flow level, and associated symptoms for you can help identify when something may be wrong. Don’t hesitate to check with your doctor if you have any concerns. With a little preparation and TLC, you can take good care of your body during your monthly cycle.