Irregular periods in teens: what is normal and when to check

Your friend gets her period every month like a clock. Yours comes after 40 days, then after 25, then not at all in December. It is easy to decide something is wrong. Most of the time, it is not. Irregular periods are common in the first 2 to 3 years after the first period, and a doctor can check whether it is simply your body settling in or something that needs care.

This is education, not a diagnosis. Your doctor decides.

What a typical cycle looks like

Day 1 is the first day of bleeding. For adults, a typical cycle is every 21 to 35 days, with bleeding that lasts 2 to 7 days. A pad changes every 3 to 4 hours or less often.

That is the yardstick, but a young body is still learning it. Each month the brain signals the ovaries, an egg sac grows, an egg is released around day 14, and the womb lining either holds or sheds. In the first years that chain does not always run on time, so ovulation can be late or skipped. Cycles then come out longer, shorter or uneven.

Why teens in particular

The conversation between brain, ovaries and womb is still being tuned. That is the plain reason. It does not mean something is wrong with you, and it does not mean you did something to cause it.

For some teens, though, irregular periods are an early sign of PCOD or PMOS. PMOS is the new official name for PCOS, and your report may say PCOD, PCOS or PMOS. In those conditions the egg often does not release, so periods become late, missed or heavy. A doctor tells the two apart, so please do not try to work it out from the internet.

When to see a doctor

Please do not wait for a perfect reason. See a doctor if:

• There is no period by age 15.
• There is no period more than 3 years after breast growth began.
• You have had no period for 3 months and you are not pregnant.
• You soak a pad every hour for 2 hours, pass large clots, bleed for more than 7 days, or have severe pain.
• Cycles are longer than 35 days again and again, or you have fewer than 8 periods a year.
• You also have acne on the jaw and chin, new dark hair on the chin, upper lip or chest, thinning at the parting, or dark velvety patches on the neck.

Get help urgently for severe lower tummy pain, fainting, very heavy bleeding, chest pain or breathlessness, or a sudden deepening of the voice with rapid hair growth.

What the doctor may do

A conversation comes first: your periods, your family, your weight, your skin and hair. Your doctor may then suggest blood tests, which can include hormones such as LH, FSH, prolactin and TSH, blood sugar, and iron, vitamin D and B12. Thyroid and prolactin problems can look like PCOD, so they are always checked.

A scan alone is not used to diagnose PCOD in the first 8 years after periods start. So even if a scan shows small follicles, the doctor goes by your whole picture. Those dots are stalled follicles, not harmful cysts.

Track your cycle

Write down the first day of every period. A phone note works. The booklet has a tracker page with columns for the start date, how many days, flow (light, medium or heavy), pain from 0 to 10 and weight.

Bring it to the appointment. Three or four months of dates tell a doctor more than any guess.

Everyday things that help

None of these is a treatment. They support the care your doctor plans.

• Sleep 7 to 9 hours, with screens off 1 hour before bed.
• Move for 150 minutes a week, in any way you enjoy. Even 10 minutes counts.
• Eat regular meals with protein, especially at breakfast. Avoid crash diets. They backfire.
• Keep some calm time each day, such as yoga, pranayama or a hobby.

Stress hormones affect insulin and ovulation, so stress can make cycles less predictable.

A word on feelings

Worry about your body, acne or hair is common. Anxiety and low mood are 2 to 3 times more common in PCOD. If sadness or worry lasts more than 2 weeks, ask for help. If you ever think of harming yourself, tell someone and get help right away. Tele-MANAS 14416 is a free helpline, open 24x7.

You are not behind. You are early in a process that takes a few years to settle, and a doctor can look at it with you.