Let’s get the obvious reasons out of the way: The most common reasons you might miss a menstrual period are pregnancy and menopause.
But there are other times when you might miss a period. It’s unlikely that you’ll have regular, uninterrupted periods throughout your 30-plus reproductive years. Missing one or more periods, called amenorrhea, is not uncommon.
Missing a period can be stressful, especially if you’re not sure what’s going on. There are several common causes for a missed or late period that have nothing to do with pregnancy. Whether you're in your 20s or 50s, it helps to understand how your menstrual cycle works and what could be affecting it.
Bailey Bylow, an OBGYN nurse practitioner with Banner - University Medicine, shared more about what you should know and when to talk to a health care provider.
How your menstrual cycle works
A typical menstrual cycle lasts about 28 days but anything from 21 to 35 days is considered normal. Hormones like estrogen and progesterone help control when your period starts and stops. If these hormones get thrown off, your cycle might change too. That could lead to:
- A late or early period
- A skipped period
- Periods that are lighter or heavier than usual
If your period hasn’t started after more than 35 days, it’s time to pay attention.
Common reasons for a missed period
1. Hormonal changes with age
If you're between 45 and 55, you may be entering perimenopause (the years leading up to menopause). Your hormone levels shift during this time, which can cause irregular periods or make your periods stop completely.
In some cases, early menopause or premature ovarian failure can cause your periods to stop before age 40. You may also notice symptoms like hot flashes, sleep issues or vaginal dryness.
2. Polycystic ovary syndrome (PCOS)
PCOS is a common condition that affects your hormone levels. If you have PCOS, your body may make high levels of androgens (male hormones). This hormonal imbalance can stop you from ovulating and lead to missed or irregular periods.
Other signs of PCOS include:
- Weight gain
- Hair growth on your face or body
- Acne
- Trouble getting pregnant
3. Weight changes or low body fat
Your body needs a healthy balance of fat and nutrients to keep your hormones working properly. Sudden weight loss, weight gain or very low body fat, which is often seen in athletes, can disrupt your cycle.
Eating disorders like anorexia or bulimia can also cause your periods to stop.
4. Stress, exercise and daily life
Your brain plays a key role in managing your hormones. High stress, poor sleep or overexercising can affect the signals your body sends to trigger your period.
If you've had a major life change, illness or are working long hours without rest, your period may come late or may not come at all.
5. Birth control
“Many people are surprised if they have changes in their periods after starting birth control. Some types of hormonal contraception can make periods lighter, less frequent or even stop them altogether. This is expected and usually not a cause for concern,” Bylow said.
If you miss a period while using a copper IUD, however, you should take a pregnancy test and contact your health care provider to look into other possible causes, including health conditions.
Other medical causes
A missed period could also be linked to:
- Thyroid problems
- Pituitary gland issues
- Ovarian insufficiency
- Other medical conditions that cause a hormonal imbalance
- Structural changes in your body
- Ovarian cysts
- Some medications
When to see a doctor
“You should consult a health care provider if you miss your period for more than three months,” Bylow said.
You should also talk to your provider if:
- You’re between 45 and 55 and not sure if it’s perimenopause
- You’re trying to get pregnant but your periods are irregular
- You have any of these other symptoms:
- Hair growth
- Acne
- Breast milk leakage when not pregnant or breastfeeding
- Unexplained weight gain or weight loss
- Hot flashes
- Headaches
- Vision changes
What happens during an evaluation?
“During evaluation, expect your provider to take a detailed history,” Bylow said. They will ask about topics like:
- Menstrual patterns
- Weight changes
- Stress
- Exercise
- Medication use
- Acne
- Hair growth
- Symptoms of other conditions
- History of sexually transmitted diseases
- Past surgeries
- Lifestyle
- Family history
They may evaluate you physically and, depending on your situation, they may order:
- Blood tests to check hormone levels like FSH, LH, estrogen, androgen, prolactin or thyroid hormones
- A pelvic ultrasound to check for PCOS or other issues
- Additional imaging depending on findings
How Banner Health can help
Missing your period isn’t always a reason to worry but it’s worth looking into, especially if it happens often. At Banner Health, our women’s health specialists offer care for hormonal imbalances, PCOS, menopause and other conditions that can affect your cycle.
We can help you find out what’s causing your missed periods and create a care plan that fits your health goals, whether that’s managing your symptoms, protecting your fertility or just getting back to feeling like yourself.
Schedule an appointment with a Banner Health provider and get the answers you need.
