Why did my period stop suddenly?

Bottom linePeriods can stop (amenorrhea when you miss 3 or more) due to pregnancy, breastfeeding, significant weight loss, excessive exercise, severe stress, PCOS/PMOS, thyroid or prolactin problems, perimenopause, or hormonal birth control; rule out pregnancy first, and see a doctor if you've had no period for 3 or more months when not pregnant or have other symptoms, since the cause is often reversible.

Periods stopping (called amenorrhea when you miss 3 or more in a row) has many possible causes. Pregnancy is the most common, but it's far from the only one.

Common causes

• Pregnancy - the first thing to rule out if you're sexually active
• Breastfeeding
• Significant weight loss or being underweight
• Excessive exercise (common in athletes)
• Severe or ongoing stress
• PCOS/PMOS
• Thyroid problems or high prolactin
• Perimenopause and menopause
• Hormonal birth control - some methods stop periods (this is normal and safe)
• Coming off the pill - it can take a few months to restart

When to see a doctor

• No period for 3 or more months and not pregnant
• Missed periods with other symptoms (headaches, vision changes, milky nipple discharge, excess hair)
• Periods that stop after being regular

Missing periods is often reversible once the cause is addressed, but it's worth investigating because long-term absence can affect bone and heart health.

Take a pregnancy test first if relevant, then track with the Menstrual Cycle Calculator. See also why is my period late.

Femora flags missed periods early so you can act sooner.