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 your periods, why medicines matter, and which headache or eyesight changes need urgent 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 can’t forecast your future fertility. Includes when to get help.
4 min read Premature ovarian insufficiency (POI) POI before 40: symptoms, tests, 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 giving birth are worth checking.
4 min read Weight, eating and your cycle How food and weight changes can affect periods, why eating problems deserve care at any size, and where to find support.
4 min read When training affects your periods: RED-S How not eating enough for your training can affect periods, bones and performance, and how to get support with food and rest.
5 min read Can stress delay your period? Sleep and exercise What the evidence says about how stress, sleep and exercise affect your cycle, what low energy availability means, and when to get a missed period checked.

Written by the Ruva 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.