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Periods & cycles

Your cycle, phase by phaseWhat actually happens each month, and what's normal.

Your menstrual cycle is the monthly process your body goes through to get ready for a possible pregnancy. It is counted from the first day of one period to the first day of the next.

The average cycle is about 28 days, but anywhere from 24 to 38 days is normal. In the first 2 to 3 years after your first period, cycles are often irregular, and that is completely normal. Tracking yours helps you learn your own pattern.

A typical 28-day cycle
Period
days 1 to 5
Follicular
Ovulation
~day 14
Luteal
Bleeding Lining rebuilds Egg released Before next period

The four phases

Days 1 to ~5 1. Menstrual phase (your period)

Because pregnancy did not happen, hormone levels drop and the lining of your uterus sheds and leaves your body as blood. Bleeding usually lasts 3 to 7 days. This is day one of your cycle.

Days 1 to ~13 2. Follicular phase

This overlaps with your period. A hormone called estrogen rises and rebuilds the lining of your uterus. At the same time, FSH helps a tiny sac (a follicle) in your ovary grow an egg. Many people feel their energy build during this phase.

Around day 14 3. Ovulation

A surge of a hormone called LH releases the mature egg from your ovary. It travels down a fallopian tube. This is the most fertile point in the cycle. The egg only survives about 12 to 24 hours.

Days ~15 to 28 4. Luteal phase

A hormone called progesterone rises to keep the lining ready in case of pregnancy. If the egg is not fertilized, estrogen and progesterone drop. That drop can bring PMS feelings like moodiness, tiredness, or cramps, and then your next period begins.

Talk to a doctor if
  • You are 15 and have not started your period
  • Your periods are still very irregular after 2 or more years
  • You bleed between periods
  • You soak through a pad or tampon in under an hour
  • A period lasts longer than about a week
  • Cramps are severe and pain relief does not help

Watch: how the menstrual cycle works (video)

How to ease period crampsSimple things that help, and when pain needs a check-up.

Cramps happen when your uterus tightens to shed its lining. For many people they ease with a heating pad or warm bath, gentle movement like walking, drinking water, and rest.

Over-the-counter pain relief such as ibuprofen can help. Ask a parent or pharmacist about the right amount for you. See a doctor if cramps are severe, get worse over time, or stop you from doing normal things.

Trusted sources
NHS ACOG KidsHealth (Nemours)
Pads, tampons and cups: how to chooseA plain comparison so you can pick what suits you.

All three work. It comes down to comfort and what you can get. The most important thing is to change them regularly to stay fresh and safe.

With tampons, do not leave one in too long, because of a rare but serious infection called toxic shock syndrome (TSS). Use the lowest absorbency that works for your flow, and change it within about 8 hours.

Quick comparison
ProductChange how oftenGood to know
PadsEvery 4 to 8 hoursWorn in your underwear. Easy to start with.
TamponsEvery 4 to 8 hours, max 8Inserted. Use lowest absorbency (lowers TSS risk).
Menstrual cupEmpty every 8 to 12 hoursReusable. Saves money over time.

Period problems & conditions

Dysmenorrhea (painful periods)The medical name for period pain.

Dysmenorrhea just means painful periods. Cramping in your lower belly before or during your period is very common, and it happens when the uterus tightens to shed its lining.

Heat, gentle movement, and pain relief like ibuprofen help many people. See a doctor if the pain is severe, keeps you from school or activities, or does not get better with usual pain relief, since it can sometimes point to another condition.

PMS (premenstrual syndrome)The physical and emotional stuff before your period.

PMS is a mix of symptoms in the days before your period, like mood swings, bloating, sore breasts, tiredness, headaches, and cravings. It happens because of normal hormone changes and usually eases once your period starts.

Sleep, movement, and eating well can take the edge off. Talk to a doctor if PMS is severe or keeps getting in the way of your life.

Trusted sources
Mayo Clinic NHS
PMDD (premenstrual dysphoric disorder)A severe form of PMS. It is real and treatable.

PMDD is a much stronger version of PMS. In the week or two before your period it can cause intense sadness, irritability, anxiety, or anger, strong enough to affect school, friendships, and daily life.

PMDD is real and it can be treated. If mood symptoms before your period ever feel overwhelming, please talk to a doctor. You do not have to just push through it.

Amenorrhea (missing periods)When periods do not come, or stop.

Amenorrhea means not having periods. It is normal not to have started yet in your early teens. It can also mean your periods stop for several months after they had started.

Common causes include stress, big changes in weight or exercise, or hormone conditions. See a doctor if you have not started your period by age 15, or if your periods stop for 3 months or more.

Trusted sources
Cleveland Clinic Mayo Clinic
EndometriosisWhen period pain is more than usual.

Endometriosis is when tissue similar to the lining of the uterus grows outside it. It can cause very painful periods, ongoing pain in the belly or pelvis, and heavy bleeding.

It often takes a long time to get diagnosed, so speaking up about pain really matters. See a doctor if your period pain is severe, getting worse, or not helped by usual pain relief.

AdenomyosisHeavy, painful periods from the uterus wall.

Adenomyosis is when lining-like tissue grows into the muscular wall of the uterus. It can cause heavy, painful periods and a feeling of pressure or fullness in the lower belly.

It is more common in adults, but it is good to know the name. See a doctor for periods that are very heavy or very painful.

Trusted sources
Mayo Clinic Cleveland Clinic
PCOS (polycystic ovary syndrome)A common hormone condition.

PCOS is a common hormone condition. Signs can include irregular or missed periods, acne, extra hair growth on the face or body, and weight changes. It is linked to higher levels of certain hormones.

PCOS can be managed with a doctor's help. See a doctor if your periods are very irregular or you notice these signs together.

Ovarian cystsFluid-filled sacs on an ovary, often harmless.

Ovarian cysts are fluid-filled sacs that can form on or in an ovary. Many are harmless, cause no symptoms, and go away on their own. Some can cause bloating or pelvic pain.

Get medical help for sudden or severe pelvic pain, especially with fever or feeling faint.

Uterine fibroidsCommon, non-cancerous growths in the uterus.

Fibroids are non-cancerous growths in or on the uterus. They are common, especially in adults, and can cause heavy periods, pelvic pressure, or no symptoms at all.

See a doctor for very heavy periods or ongoing pelvic pain.

Thyroid problemsA gland that affects energy and periods.

The thyroid is a small gland in your neck that controls how your body uses energy. If it makes too much hormone (hyperthyroidism), you might feel a racing heart, weight loss, feeling hot, shakiness, anxiety, or changes in your periods. Thyroid problems are more common in women.

See a doctor if you notice these symptoms. A simple blood test can check your thyroid.

Toxic shock syndrome (TSS)Rare but serious, linked to tampons.

TSS is a rare but serious infection that can be linked to leaving a tampon in too long. Warning signs during your period include a sudden high fever, a sunburn-like rash, vomiting, diarrhea, dizziness, or feeling very unwell.

If you feel very sick while using a tampon, take it out and get medical help right away. Lower your risk by changing tampons every 4 to 8 hours and using the lowest absorbency you need.

Body & puberty

A girl's guide to pubertyBody changes and first periods, explained kindly.

Puberty is when your body slowly changes from a kid's body into an adult's. For girls it usually starts between about age 8 and 13, and the whole process takes several years.

It tends to follow a rough order: breasts start to develop first (often the earliest sign), then body hair grows and you have a growth spurt, and your first period usually comes about 2 to 3 years after breasts begin. Everyone's timing is different and there is no "right" pace.

It is worth talking to a doctor if puberty starts very early (before age 8) or has not started by about age 14, since a doctor can check that everything is on track.

Everyday hygiene, myth-freeWhat's healthy and totally normal for your body.

Your vagina cleans itself, so you do not need special washes or products inside it. Just wash the outside with warm water and a gentle soap.

Clear or white discharge is normal and changes a little through your cycle. See a doctor if discharge smells strong, turns green or grey, or comes with itching or burning.

Body image & confidence

Your body is changing, and that's okayWhy bodies look different, and when to reach out.

Puberty changes your body a lot, and it happens at a different pace for everyone. Two people the same age can look completely different and both be perfectly healthy. There is no single "right" way for a body to look, even though social media and ads can make it feel that way.

Some days you might like how you look and other days you might not. Both are normal, and how you feel does not change your worth. Your body is yours, and it carries you through everything you do.

If you find yourself thinking about your weight or looks a lot, comparing yourself to others, or changing how you eat to change your body, that is worth taking seriously. Please talk to an adult you trust or a doctor. You deserve support, and these feelings can get better.

Social media and comparisonWhy feeds aren't real life.

Photos online are often filtered, posed, and picked from hundreds of tries, so they are not real life. Comparing yourself to them can quietly hurt your mood and confidence.

It can help to follow accounts that make you feel good, take breaks from scrolling, and remember that everyone's highlight reel hides normal, messy days.

Mind & mood

Mood swings and big feelingsWhy feelings shift, and gentle ways to cope.

During the teen years your brain and hormones are changing fast, so feelings can be stronger and change quickly. That is normal.

Things that help: getting enough sleep, moving your body, talking to someone, and spending time outside. If low or anxious feelings stick around or get in the way of daily life, that is a sign to reach out.

A 5-minute calming exerciseA simple breathing practice for hard moments.

When you feel panicky or overwhelmed, slow breathing tells your body it is safe. Try "square breathing":

Square breathing
  1. Breathe in slowly through your nose for 4 counts
  2. Hold your breath for 4 counts
  3. Breathe out slowly for 4 counts
  4. Hold for 4 counts, then repeat for a few minutes
Trusted sources
NHS Mental Health Mayo Clinic
When to ask for helpSigns it's more than a bad week, and who to turn to.

Everyone has bad days, but some feelings need more support. It is worth reaching out if you notice signs like these lasting for weeks:

Signs to take seriously
  • A sad or empty mood that lasts weeks
  • Losing interest in things you used to enjoy
  • Feeling hopeless, alone, or worthless
  • Big changes in your sleep, eating, or energy
  • Trouble keeping up at school

Talk to a parent, teacher, school counselor, or doctor. Depression gets better with the right care.

If you ever think about hurting yourself, tell a trusted adult now.
US: call or text 988, or text HOME to 741741

School & stress

Handling school and exam stressPressure is real. Here's how to take the edge off.

A little stress before a test is normal and can even help you focus. Too much can make it hard to sleep or think clearly.

Things that help
  1. Break big tasks into small steps
  2. Study in short blocks with real breaks
  3. Sleep before a test instead of cramming all night
  4. Ask a teacher when you are stuck, that is what they are there for

Your worth is not your grades. If stress feels constant, talk to someone you trust.

Friends & relationships

Friendships, drama and peer pressureHealthy friendships, and spotting ones that aren't.

Good friends respect you, listen, and are happy for you. Friendships can hit rough patches, but you should not feel scared, controlled, or pushed into things you do not want to do.

It is okay to step back from a friendship that keeps making you feel bad. Saying no does not make you a bad friend.

Trusted sources
KidsHealth (Nemours) ReachOut
Respect, boundaries and consentWhat respect looks like, and the warning signs.

A healthy relationship of any kind is built on respect, trust, and feeling safe to say no. Consent means everyone freely agrees, every time, and anyone can change their mind.

Warning signs to watch for: someone who pressures you, checks your phone, puts you down, or makes you feel afraid. You deserve to be treated well.

Sexual health

STIs and safer sexThe basics, with no judgment.

Sexually transmitted infections (STIs) are passed through sexual contact. Many have no obvious symptoms, so getting tested is how people actually know. Safer sex, like using condoms, lowers the risk of both STIs and unplanned pregnancy.

If you are sexually active, talking to a doctor or clinic about testing is private, normal, and nothing to be embarrassed about.

Contraception optionsThe main types, and how they differ.

Contraception (birth control) helps prevent pregnancy. There are many kinds: condoms, the pill, patches, rings, injections, implants, and IUDs. They work in different ways and each has its own pros and cons.

Condoms are the only method that also lowers the risk of STIs. A doctor or clinic can help you understand what fits your body and your life.

Other reasons for birth controlIt is not only about preventing pregnancy.

Doctors also prescribe birth control to help with health problems, not just to prevent pregnancy. It can help with painful or heavy periods, very irregular cycles, PMS and PMDD, acne, and conditions like PCOS and endometriosis.

If a period problem is affecting your life, ask a doctor whether this could be an option for you.

Staying safe online

Staying safe onlinePrivacy, strangers, and trusting your gut.

Keep personal details private, like your full name, address, school, and where you are. People online are not always who they say they are.

Do not share photos you would not want others to see, and never feel forced to. If someone online makes you uncomfortable, stop talking to them and tell a trusted adult.

Food & energy

Fueling your body wellEasy, no-pressure tips for steady energy.

Food is fuel, not something to feel guilty about. Eating regular meals with a mix of foods keeps your energy and mood steady, and growing teens need plenty of it.

Iron matters during your period years. Foods like beans, leafy greens, and meat can help you get enough. If you ever have worries about food or eating, talk to a doctor.

Every guide is checked by a doctor, nurse, or counselor and updated regularly. This is general information, not personal medical advice, for your own situation, talk to a professional.