SPM y síntomas del ciclo
Tiredness and sleep across the cycle
Revisado: 4 de octubre de 2026
Solo en inglés por ahoraFeeling more tired or sleeping badly before a period is common. Here is why it happens, what can help, and when tiredness is worth getting checked.
Why you may feel more tired
Tiredness and sleep changes are common signs of premenstrual syndrome (PMS). Some people sleep badly before a period, while others sleep more than usual. Many find it harder to fall asleep and stay asleep in the days before a period. Hormone changes are thought to play a part. These sleep problems usually ease within a few days of bleeding starting.
Sleep and PMDD
Sleep problems are also common in premenstrual dysphoric disorder (PMDD), a severe form of PMS. Being unable to sleep (insomnia) is a common symptom of PMDD and can sometimes be severe. Lack of sleep is also linked to low mood and anxiety, and it can make premenstrual moodiness worse.
Heavy periods and low iron
Tiredness can also have other causes. Heavy periods are a very common cause of iron deficiency anaemia. This is when a lack of iron means your body cannot make enough healthy red blood cells. Signs include tiredness and lack of energy, shortness of breath, noticeable heartbeats (palpitations), paler skin than usual and headaches. A blood test can check for it. If your levels are low, iron tablets are usually recommended.
Habits that help you sleep
Try to go to bed and wake up at the same time every day, and keep your bedroom dark, cool and quiet. A calming bedtime routine, such as reading, music or gentle yoga, can help you wind down. Avoid caffeine, alcohol and nicotine for at least 5 hours before bed, and try to avoid bright screens just before you sleep. Most adults need at least 7 hours of sleep a night.
Staying active and easing symptoms
Regular aerobic exercise through the month can ease tiredness, low mood and poor focus linked to PMS. Being active during the day helps sleep, but try not to exercise in the 5 to 6 hours before bed. Some studies suggest calcium may help with PMS tiredness. If cramps keep you awake, painkillers such as ibuprofen or paracetamol may help. Noting tiredness and sleep in Ciclo with a tag or note can show whether they follow your cycle.
When to see a doctor or nurse
See a doctor or nurse if tiredness or poor sleep affects your daily life, or if lifestyle changes have not helped. Also get checked if your periods are heavy or you have signs of anaemia, such as breathlessness or palpitations. If you feel faint, or have chest pain or trouble breathing, get emergency help. If low mood, anxiety or anger before your period is severe, ask about PMDD. If you are thinking about harming yourself, get emergency help or contact a crisis line now.
This is general information, not a diagnosis. If tiredness affects your daily life, talk to a doctor or nurse.