High prolactin causes

High prolactin levels can be caused by a prolactin-producing pituitary tumour (prolactinoma), certain medications (particularly some antipsychotics and antidepressants), an underactive thyroid, pregnancy and breastfeeding (a normal physiological cause), stress, or, in some cases, no clear identifiable cause. Prolactinomas are one of the more common specific causes when a clear pituitary or hormonal explanation is found. Identifying the specific underlying cause guides the most appropriate management approach.

In women, symptoms can include irregular or absent periods, unexpected milk production (galactorrhoea) unrelated to breastfeeding, and reduced fertility. In men, symptoms can include reduced libido, erectile dysfunction, and, less commonly, breast enlargement or unexpected milk production. Some people, particularly with mild elevations, have few or no obvious symptoms, and the finding is picked up incidentally during investigation for another reason such as reduced fertility.

The hormonal effects of high prolactin, such as reduced fertility and reduced sex hormone levels, can have significant impact on wellbeing and long-term bone health if untreated over an extended period. If caused by a pituitary tumour, particularly a larger one, there can also be effects related to the tumour itself, such as pressure on nearby structures affecting vision, in addition to the hormonal effects. With appropriate diagnosis and treatment of the underlying cause, most of these effects can be effectively managed or reversed.

Investigation typically starts with reviewing medications that could be responsible, checking thyroid function, and considering pregnancy as a cause in women of childbearing age, alongside blood tests to confirm and quantify the prolactin elevation. If no other clear cause is found, or the prolactin level is quite high, an MRI scan of the pituitary gland is used to look for a prolactin-producing tumour (prolactinoma). An endocrinologist typically coordinates this structured investigation approach.

Treatment depends on the underlying cause: medication-induced hyperprolactinaemia may improve with a change in the responsible medication under medical guidance, while an underactive thyroid is treated with thyroid hormone replacement, which can also normalise prolactin. A prolactinoma is often very effectively treated with specific medication (dopamine agonists) that shrinks the tumour and normalises prolactin levels in most cases, avoiding the need for surgery in the majority of patients. Regular monitoring, including repeat blood tests and sometimes imaging, tracks response to treatment.

When caused by a reversible factor such as a specific medication or an underactive thyroid, treating that underlying cause often normalises prolactin levels completely. Prolactinomas, while not always fully "cured" in the sense of the tumour disappearing entirely, are usually very effectively controlled long-term with medication, normalising prolactin levels and associated symptoms for the great majority of patients. Regular endocrinology follow-up helps ensure ongoing effective control and monitors for any changes over time.

Prolactin naturally rises during pregnancy and breastfeeding as part of normal physiology, preparing the body for and supporting milk production, and this is not a cause for concern. Pathological hyperprolactinaemia occurs outside of pregnancy or breastfeeding and needs proper investigation to identify an underlying cause, such as medication, thyroid problems, or a pituitary tumour. A doctor will always consider and exclude pregnancy as a first step, particularly in women of childbearing age presenting with irregular periods and possible high prolactin symptoms, before pursuing further investigation.

See a doctor if you have symptoms such as irregular periods, unexpected milk production, or reduced libido and fertility, so appropriate blood tests can be arranged to check for high prolactin and its likely cause. A private endocrinology assessment can typically be arranged within about one to two weeks. If a pituitary tumour is identified as the cause, ongoing specialist endocrinology follow-up is important for monitoring treatment response and long-term management.