How many days can a girl's menstrual period be delayed at the latest?

Mar 14, 2025 Source: Cainiu Health
Disease description:

My period hasn't arrived yet this month. Although it occasionally arrives late, this time it's been longer than usual. I'm a bit worried and would like to ask, how delayed can a woman's period be at the longest? Is my situation normal?

Doctor's answer (1)
Dr. Zhang Lu

The normal range for a woman's menstrual cycle is typically 21 to 35 days. There is no fixed maximum number of days for menstrual delay, and a delay of up to 7 days is generally considered normal.

If a woman's menstrual cycle is usually regular, for example occurring every 28 days, a delay of 7 days or less is typically considered a normal physiological variation. Once the menstrual period is delayed beyond 7 days, reaching or exceeding 35 days, it can be considered as menstrual delay, which warrants attention.

Menstrual delay may be caused by various factors including, but not limited to, stress, weight changes, hormonal fluctuations, illness, medication effects, and pregnancy. Women of childbearing age should consider pregnancy as a potential cause.

In some special cases, menstrual delay may exceed 7 days. For example, prolonged excessive stress, sudden changes in living environment, or extreme dieting leading to endocrine disorders can cause a delay of 10 days or even longer.

Conditions such as polycystic ovary syndrome (PCOS) and hypothyroidism can also affect the menstrual cycle, causing delays that may last for weeks or even months.

If physical discomfort or symptoms arise, it is recommended to seek medical attention at a hospital promptly and follow the doctor's instructions for appropriate management.