Hormones and your body: thyroid, prolactin and more

How hormones beyond the cycle itself can change your periods, and what blood tests can and can’t tell you.

4 min read High prolactin (hyperprolactinaemia) What high prolactin can mean for periods, why medicines matter, and which headache or vision changes need urgent help. Includes when to get help.
4 min read Hormone blood tests: what they can and cannot tell you What common hormone tests look for, why timing matters, and why an AMH result is not a forecast of your future fertility.
4 min read Premature ovarian insufficiency (POI) POI before 40: symptoms, assessment, hormone treatment, bone and heart health, fertility options and emotional support. Includes when to get help.
4 min read Thyroid conditions and your cycle How thyroid conditions can affect periods, fertility and pregnancy, and why symptoms after a birth deserve attention. Includes when to get help.
4 min read Weight, eating and your cycle How nutrition and weight changes can affect periods, why eating difficulties deserve care at any size, and where to find support.
4 min read When training affects your periods: RED-S How under-fuelling can affect periods, bones and performance, and how to ask for support with food, training and recovery.
5 min read Can stress delay your period? Sleep and exercise What evidence says about stress, sleep and exercise affecting your cycle, including low energy availability and when missed periods need checking.

Written by the Veya team from the sources listed in each guide. They aren’t medical advice; if you’re worried about a symptom, talk to a doctor, nurse or pharmacist.