Quick Answer
Occasionally missing a period can be normal due to stress, weight changes, or exercise. However, if you're sexually active, take a pregnancy test. See a doctor if you miss 3+ periods, have other symptoms, or are concerned.
🚨 See a Doctor Promptly If:
- Positive pregnancy test with severe abdominal pain or heavy bleeding
- Sudden vision changes or severe headaches with missed period
- Milky nipple discharge (not breastfeeding)
- Excessive hair growth (face, chest, back) with missed periods
- You're under 15 and haven't started periods
📅 Schedule an Appointment If:
- • Missed 3 or more consecutive periods
- • Previously regular cycles become irregular
- • Periods stop after age 15-16 and haven't returned
- • No period by age 16 (primary amenorrhea)
- • Significant weight loss or gain (15+ pounds)
- • New medications affecting your cycle
- • Excessive exercise (training for athletics)
- • Signs of PCOS: acne, weight gain, excess hair
Common Causes of Missed Periods
1. Pregnancy (Most Common)
- • First step: Take a home pregnancy test if sexually active
- • When to test: First day of missed period or 2 weeks after unprotected sex
- • Early pregnancy signs: Breast tenderness, nausea, fatigue, frequent urination
- • Action: Positive test? Schedule prenatal care appointment
2. Stress
- • How: Stress hormones (cortisol) can suppress reproductive hormones
- • Common triggers: Major life changes, exams, work stress, grief
- • Duration: Usually returns within 1-2 cycles when stress resolves
- • Solution: Stress management, adequate sleep, self-care
3. Weight Changes
- • Low body weight: BMI under 18.5, eating disorders, excessive calorie restriction
- • Rapid weight loss: 15+ pounds in short period
- • Obesity: Excess body fat produces estrogen, disrupting cycle
- • Why it matters: Body needs certain fat percentage for ovulation
4. Polycystic Ovary Syndrome (PCOS)
- • What it is: Hormonal disorder affecting 1 in 10 women
- • Symptoms: Irregular periods, acne, excess facial/body hair, weight gain
- • Why periods stop: Elevated androgens prevent regular ovulation
- • Treatment: Birth control pills, metformin, lifestyle changes
5. Excessive Exercise
- • Athletic amenorrhea: Common in endurance athletes, dancers, gymnasts
- • Cause: Low body fat + high energy expenditure
- • Risk: Bone density loss (stress fractures), infertility
- • Solution: Increase calorie intake, reduce training intensity
6. Birth Control
- • Hormonal IUD: 20% of users stop periods (this is normal)
- • Birth control pills: Very light periods or none on continuous pills
- • Depo-Provera shot: 50% stop periods after 1 year
- • After stopping: May take 3-6 months for periods to return
7. Thyroid Disorders
- • Hypothyroidism: Underactive thyroid causes irregular/missed periods
- • Hyperthyroidism: Overactive thyroid causes light/infrequent periods
- • Other symptoms: Fatigue, weight changes, hair loss, mood changes
- • Diagnosis: Simple blood test (TSH level)
8. Perimenopause
- • Age range: Typically 40s, but can start in 30s
- • Early signs: Irregular cycles, skipped periods, hot flashes
- • Duration: Can last 4-10 years before menopause
- • Note: Still possible to get pregnant during perimenopause
What Your Doctor Will Check
Medical History
- • Age of first period
- • Normal cycle pattern
- • Sexual activity and contraception
- • Medications and supplements
- • Stress levels and lifestyle
- • Weight changes, exercise routine
Physical Exam & Tests
- • Pregnancy test: First step
- • Pelvic exam: Check reproductive organs
- • Blood tests: Hormones (FSH, LH, prolactin, thyroid, androgens)
- • Ultrasound: If PCOS suspected (check ovaries)
- • Progesterone challenge: Test if uterine lining responds
When It's Normal to Miss a Period
- • First 2 years after menarche: Cycles often irregular in teens
- • Breastfeeding: Lactational amenorrhea is normal
- • Recent childbirth: May take 6+ weeks to resume
- • On birth control: Designed to stop or lighten periods
- • Occasional stress: One missed period from major stress is common
- • Perimenopause: Expected in late 40s-early 50s
Self-Care & Prevention
- • Maintain healthy weight: BMI 18.5-24.9 optimal for regular cycles
- • Balanced nutrition: Adequate calories, healthy fats, protein
- • Moderate exercise: Avoid overtraining (more isn't always better)
- • Stress management: Meditation, yoga, therapy, adequate sleep
- • Track your cycle: Apps help identify patterns and irregularities
- • Limit alcohol: Excessive drinking can disrupt hormones
- • Adequate sleep: 7-9 hours nightly for hormone regulation
Medical Review
Reviewed by: Ricardo Hamilton, MD
Last Updated: November 26, 2025
Sources: American College of Obstetricians and Gynecologists (ACOG), Mayo Clinic, National Institutes of Health (NIH)