THE CHROMOSOME | Clinical Content Series
Hyperprolactinaemia
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She was 29 years old and had not had a regular menstrual cycle in three years. She had gained 22 kilograms in that same period. She was not pregnant, she had been checked repeatedly. She was not breastfeeding. She had no obvious reason, by any standard clinical measure, for the milky discharge from her breasts that she had been too embarrassed to mention to her previous physicians until it had become impossible to ignore.
When she finally disclosed it I understood immediately why every other diagnosis had been wrong.
Prolactin. The hormone of lactation. The hormone the body produces in abundance after childbirth to sustain milk production and, critically, to suppress ovulation and fertility during that period. In her body it was elevated to three times the upper limit of normal with no pregnancy, no breastfeeding, and no apparent reason that her previous physicians had thought to investigate.
She had been told her irregular periods were PCOS. She had been given the contraceptive pill. She had been told her weight gain was dietary. She had been given a diet sheet. Neither intervention had addressed the single hormonal abnormality driving everything she was experiencing.
Her MRI revealed a small prolactinoma, a benign tumour of the pituitary gland producing prolactin continuously and autonomously, without the regulatory signals that should have kept it in check. It was small enough to have been missed on a less detailed scan. It was large enough to have disrupted her hormonal life entirely for three years.
This is the detail about hyperprolactinaemia that Pakistani medicine consistently misses. It does not always announce itself with obvious symptoms. It masquerades as PCOS, as unexplained weight gain, as infertility, as low mood. It is identified only when prolactin is measured, and prolactin is measured only when a physician thinks to order it.
I think to order it. Always.
The FTO gene's influence on dopaminergic regulation, the neurotransmitter system that normally suppresses prolactin release, creates a predisposition in Pakistani patients to prolactin dysregulation that sits beneath the surface of many obesity presentations I evaluate. It is not always a prolactinoma. Sometimes it is functional hyperprolactinaemia, chronically elevated prolactin driven by stress, by medications, by hypothyroidism, by the disrupted dopamine signalling that the FTO metabolic profile promotes. In either case the consequence for weight, for reproductive function, and for metabolic health is the same.
We treated her prolactinoma through the appropriate medical pathway. We simultaneously addressed the secondary hormonal consequences, the suppressed oestrogen, the disrupted ovulation, the metabolic deterioration. Within eight months her prolactin had normalised, her periods had returned, and she had lost 14 kilograms without any dietary intervention beyond the metabolic recalibration her body had needed all along.
She had been carrying the wrong diagnosis for three years. The right diagnosis took one blood test and one MRI.
That is the cost of not asking the right questions.
FAQs
Hyperprolactinaemia is a condition of chronically elevated prolactin, the hormone primarily responsible for milk production after childbirth. When prolactin is elevated outside of pregnancy and breastfeeding it suppresses oestrogen and testosterone production, disrupts ovulation, impairs dopamine signalling, promotes fat storage particularly around the abdomen and hips, and drives persistent low mood and fatigue. In Pakistani women it is a significantly underdiagnosed cause of unexplained weight gain because prolactin is rarely included in standard hormonal panels unless galactorrhoea, milky breast discharge, is present. Dr. Zaar measures prolactin as a routine component of every female obesity assessment precisely because its absence from standard panels creates a systematic diagnostic blind spot.
While a prolactinoma, a benign pituitary tumour, is the most recognised cause, hyperprolactinaemia in Pakistani patients more frequently arises from functional causes that are rarely investigated. Chronic psychological stress elevates prolactin through hypothalamic dopamine suppression. Hypothyroidism drives prolactin elevation through TRH stimulation of the pituitary. Medications including antipsychotics, antidepressants, antihypertensives, and antiemetics, all widely prescribed in Pakistan, are potent prolactin elevators. Polycystic ovarian syndrome and insulin resistance both create hormonal environments that promote prolactin dysregulation. Dr. Zaar evaluates every potential driver systematically, because treating the prolactin without identifying its source produces only temporary results.
The FTO gene at Chromosome 16q12.2 influences dopaminergic signalling pathways in the hypothalamus, and dopamine is the primary inhibitory regulator of prolactin release from the pituitary. When FTO associated metabolic dysfunction disrupts hypothalamic dopamine tone, the inhibitory brake on prolactin production is weakened, allowing prolactin to rise without the stimulus of pregnancy or breastfeeding. In Pakistani patients, this dopaminergic vulnerability intersects with chronic stress, sleep disruption, and the inflammatory consequences of visceral obesity to create a prolactin environment that is persistently dysregulated. Dr. Zaar identifies this pattern through clinical assessment and targeted hormonal investigation rather than genetic testing.
Prolactin exerts its most significant reproductive effect through suppression of GnRH, the hypothalamic signal that drives LH and FSH production from the pituitary. Without adequate LH and FSH, oestrogen production falls, ovulation is suppressed, and the menstrual cycle becomes irregular or absent entirely. This is the mechanism through which the body naturally prevents pregnancy during breastfeeding, and in hyperprolactinaemia it operates pathologically outside that context. Pakistani women with elevated prolactin are frequently misdiagnosed with PCOS because the hormonal picture, irregular periods, anovulation, weight gain, is superficially identical. The critical distinction is made only when prolactin is measured, which requires a physician who includes it in their diagnostic thinking.
Elevated prolactin drives weight gain through several simultaneous mechanisms that dietary restriction cannot address. It suppresses oestrogen, reducing the metabolic protection that oestrogen normally provides against visceral fat accumulation. It impairs dopamine signalling, which reduces motivation, disrupts reward pathways around food, and promotes compulsive eating behaviour. It promotes insulin resistance directly through its effects on pancreatic beta cell function. And it disrupts sleep architecture, elevating ghrelin and suppressing leptin in ways that intensify hunger and reduce satiety independently of actual caloric intake. A patient with untreated hyperprolactinaemia is fighting metabolic headwinds on every front simultaneously. No diet overcomes this. Treating the prolactin does.
Yes, and this is one of the most clinically important and most overlooked relationships in Pakistani medicine. Dopamine antagonist medications including metoclopramide, domperidone, haloperidol, risperidone, and several antihypertensive agents elevate prolactin by blocking the dopamine receptors that normally inhibit its release. These medications are prescribed extensively in Pakistan, metoclopramide and domperidone for digestive complaints, antipsychotics for a wide range of conditions including anxiety and insomnia, antihypertensives for blood pressure management. Pakistani patients on these medications frequently develop significant weight gain that is attributed to lifestyle rather than to the prolactin elevation the medication is producing. Dr. Zaar evaluates medication history as a critical diagnostic step in every hyperprolactinaemia assessment.
Prolactin and dopamine exist in a direct inverse relationship, when prolactin rises, dopamine falls. Dopamine is the neurotransmitter of motivation, reward, pleasure, and drive. Its suppression by elevated prolactin produces a clinical picture of low mood, anhedonia, reduced motivation, social withdrawal, and cognitive slowing that is frequently indistinguishable from clinical depression. Pakistani patients with hyperprolactinaemia are commonly prescribed antidepressants, many of which further elevate prolactin, deepening the hormonal disruption they are meant to treat. THE CHROMOSOME protocol identifies this cycle and breaks it, treating the prolactin dysregulation directly rather than managing its psychological consequences with medications that worsen its biological cause.
Hyperprolactinaemia in men is less common than in women but significantly more damaging when present, and almost never diagnosed in Pakistani clinical practice. Elevated prolactin suppresses testosterone through the same GnRH suppression mechanism that disrupts female reproductive function, producing hypogonadism with its associated weight gain, muscle loss, fatigue, low mood, and sexual dysfunction. Pakistani men with this combination are almost universally told they are depressed or simply ageing. The prolactin is never measured. The testosterone deficiency is never attributed to its correct hormonal origin. Dr. Zaar includes prolactin assessment in male obesity evaluations as a standard diagnostic step, because the consequences of missing it are profound and the test that identifies it costs almost nothing.