Stress
Why it affects periods, sleep and energy
Stress is not just emotional — it creates physical changes throughout the body. When you feel stressed, your brain signals the release of cortisol, the main stress hormone. Cortisol is helpful in short bursts, but when stress is constant, it starts to interfere with hormones, sleep, digestion and energy.
What this feels like in real life
• Always feeling “on edge” even where nothing is urgent
• Waking up tired despite sleeping
• Feeling like your body never fully relaxes
Stress and the menstrual cycle
Chronic stress disrupts communication between the brain and ovaries. Research shows this can delay ovulation, lengthen cycles or increase symptoms such as pain and PMS (Human Reproduction Update, 2017: https://academic.oup.com/humupd).
What this feels like in real life
• Periods arriving later than expected
• Cycles becoming unpredictable
• PMS feeling stronger or lasting longerWhen stress is combined with undereating, skipped meals or excessive exercise, the body may switch off ovulation altogether. This is called functional hypothalamic amenorrhoea and is a recognised stress response (Endocrine Society Clinical Guidelines, 2017: https://www.endocrine.org).
Stress and sleep
Cortisol should be low at night to allow sleep. Ongoing stress keeps cortisol elevated, making it harder to fall asleep and stay asleep (Sleep Medicine Reviews, 2019: https://www.sciencedirect.com/journal/sleep-medicine-reviews).
What this feels like in real life
• Feeling wired but exhausted at bedtime
• Waking during the night with racing thoughts
• Light, unrefreshing sleep