Your Cycle, Explained
Your menstrual cycle is so much more than just your period. It's a monthly rhythm of hormones, energy shifts, and body changes — and understanding it can be genuinely empowering.
The Four Phases of Your Cycle
Every cycle moves through four phases. Understanding each one helps you make sense of how your body and mood shift throughout the month.
Menstrual Phase
Days 1–5 (average)
Your period arrives
This is when your uterine lining sheds because pregnancy didn't occur. Estrogen and progesterone are at their lowest, which triggers the bleed. You may feel tired, crampy, or low-energy — that's completely normal.
Hormones
Estrogen and progesterone drop to their lowest levels
Body Changes
Uterine lining sheds; flow ranges from light to heavy
How You Might Feel
Tired, crampy, lower back ache, bloated, or emotionally low
Follicular Phase
Days 1–13 (overlaps with menstrual)
Your body gears up
The pituitary gland releases FSH (follicle-stimulating hormone), prompting your ovaries to develop follicles. One follicle becomes dominant and produces estrogen, which rebuilds the uterine lining and boosts your mood and energy.
Hormones
FSH rises; estrogen climbs steadily
Body Changes
Uterine lining thickens; one follicle matures in the ovary
How You Might Feel
More energetic, sociable, and clear-headed as estrogen rises
Ovulation Phase
Around Day 14 (varies)
An egg is released
A surge of LH (luteinizing hormone) triggers the dominant follicle to release a mature egg. The egg travels down the fallopian tube toward the uterus. This is the only time in your cycle you can get pregnant — the egg survives 12–24 hours, but sperm can live up to 5 days.
Hormones
LH surges; estrogen peaks then dips
Body Changes
Egg released from ovary; cervical mucus becomes clear and stretchy
How You Might Feel
Peak energy and confidence; some people feel a twinge of pain (mittelschmerz)
Luteal Phase
Days 15–28 (average)
Your body prepares
The empty follicle becomes the corpus luteum and releases progesterone to maintain the uterine lining in case of pregnancy. If no fertilized egg implants, the corpus luteum breaks down, progesterone drops, and your period begins — starting the cycle again.
Hormones
Progesterone rises; estrogen has a smaller second peak
Body Changes
Uterine lining stays thick; body temperature rises slightly
How You Might Feel
PMS symptoms may appear: bloating, mood shifts, breast tenderness, fatigue
Period Symptoms & How to Manage Them
Cramps, bloating, mood changes — these are real and common. Here's what's behind them and what actually helps.
Cramps (Dysmenorrhea)
Why it happens: Prostaglandins cause the uterus to contract to shed its lining
- Ibuprofen or naproxen taken before cramps peak works best
- Heat pads on your lower abdomen or back
- Light movement like walking or yoga
- Staying hydrated
Bloating
Why it happens: Hormonal shifts cause your body to retain water before and during your period
- Reduce salty foods in the days before your period
- Stay hydrated — it sounds counterintuitive but helps
- Gentle movement helps move things along
- Magnesium supplements may reduce water retention
Mood Changes & PMS
Why it happens: Progesterone and estrogen fluctuations affect serotonin levels in the brain
- Track your mood alongside your cycle to spot patterns
- Regular sleep, exercise, and low-sugar diet can help
- Talk to a doctor if PMS is severely affecting your daily life (it could be PMDD)
- Journaling or talking to someone you trust
Fatigue
Why it happens: Blood loss lowers iron levels; hormonal dips reduce energy
- Eat iron-rich foods: leafy greens, beans, red meat, fortified cereals
- Rest when you need to — your body is doing real work
- Vitamin C helps your body absorb iron
- If fatigue is severe, ask your doctor about checking your iron levels
Headaches
Why it happens: Estrogen drops just before your period can trigger headaches or migraines
- Stay hydrated and don't skip meals
- OTC pain relievers like ibuprofen
- Track whether headaches follow a cycle pattern
- Hormonal birth control can help some people; talk to your doctor
How Stress, Diet & Exercise Affect Your Cycle
Your cycle is sensitive to what's happening in your life. These factors can shift your timing, flow, and how you feel.
Stress
High stress raises cortisol, which can suppress the hormones that trigger ovulation. This can delay or skip your period entirely. Chronic stress may cause irregular cycles or make PMS symptoms worse.
Good to know
Even short-term stress (like exams) can shift your cycle by a few days. If you're consistently late or missing periods, stress is worth considering.
Diet & Nutrition
Severely restricting calories or losing a lot of weight quickly can stop ovulation — your body needs enough energy to run a cycle. On the flip side, a balanced diet rich in iron, magnesium, and omega-3s can ease symptoms.
Good to know
You don't need to eat perfectly. Focus on not skipping meals and getting enough iron, especially during your period.
Exercise
Moderate exercise is great for your cycle — it reduces cramps, boosts mood, and can ease PMS. But very intense training (like elite athletics) combined with low body fat can stop periods altogether, a condition called amenorrhea.
Good to know
If your period disappears after starting an intense training program, talk to a doctor. Missing periods isn't a sign of fitness — it's a sign your body needs more fuel.
When to See a Doctor
Most cycle variations are normal, but some signs are worth checking out. You deserve answers — and a good doctor won't make you feel dramatic for asking.
- Periods that are consistently shorter than 21 days or longer than 35 days apart
- Missing 3 or more periods in a row (and you're not pregnant)
- Extremely heavy bleeding — soaking through a pad or tampon every hour for several hours
- Severe cramps that don't respond to OTC pain relievers or interfere with daily life
- Bleeding between periods or after sex
- PMS so severe it affects your relationships, school, or work (this may be PMDD)
- Sudden changes in your cycle with no obvious cause (like new stress or weight change)
You don't need to have a "serious" reason to see a doctor about your period. If something feels off or is affecting your quality of life, that's enough.
Frequently Asked Questions
Keep exploring menstrual health
Learn about conditions that can affect your cycle, or explore our full resource directory.