Hot flush in males: Why it happens and how to stop the heat

A hot flush in males is not “just stress” or a mystery problem. It is usually a sign that testosterone and your brain’s temperature controls are out of sync. Here is how to tell what is driving it and which treatments actually help.

The relationship

A hot flush in males, also called a hot flash, is a sudden feeling of intense heat that usually starts in the chest, neck, or face and often comes with sweating, a pounding heart, and sometimes chills afterward. For many men it feels like someone turned on a heat lamp inside the body.

In men, the most common driver of hot flushes is a fall in testosterone. Testosterone is the main male sex hormone. It supports muscle, energy, sex drive, mood, and also helps the brain keep body temperature steady. When testosterone levels drop, the brain’s “thermostat” can become oversensitive and trigger heat dumps as hot flushes.

Testosterone levels tend to decline slowly from a man’s 40s onward, but some men see sharper drops because of medical treatments or health conditions. In one community study from Sweden, roughly one third of men aged 55 to 75 reported hot flushes at least once a week, showing that this is not a rare or fringe symptom. Men on treatments that deliberately lower testosterone, such as androgen deprivation therapy for prostate cancer, can have hot flush rates as high as 70 to 80 percent.

How it works

To understand why a hot flush in males happens, it helps to know how the brain, hormones, and blood vessels talk to each other.

The brain’s thermostat and the “comfort zone”

The hypothalamus is a small region deep in the brain that works like a thermostat and control center for body temperature and hormones. It keeps your core temperature within a narrow “comfort zone” called the thermoneutral zone. When testosterone drops, the thermoneutral zone narrows so much that even tiny changes in body temperature can trigger aggressive cooling responses such as flushing and sweating.^,[1]

Testosterone and blood vessel “overreaction”

Blood vessels in the skin normally widen or narrow to help lose or conserve heat. Testosterone influences the nerves and chemical messengers that control those vessels. When testosterone falls, signaling through pathways like norepinephrine and calcitonin gene-related peptide becomes unbalanced, which can cause sudden widening of blood vessels in the face, neck, and chest. This rush of warm blood to the skin creates the feeling of a hot flush in males and often triggers heavy sweating as the body tries to cool down.^,[2]

Why rapid testosterone drops hit harder

Men can lose testosterone slowly with age, or very quickly with medical treatments that shut down testosterone production. Androgen deprivation therapy, which is used for many prostate cancers, can push testosterone from normal levels down to castrate range within weeks. Studies show that men on these therapies report hot flushes much more often and with greater intensity than men whose testosterone drifts down slowly over years.

Meta analyses indicate that symptomatic men with total testosterone below 350 ng/dL, about 12 nmol/L, are most likely to benefit from testosterone replacement therapy. If total testosterone is borderline, free testosterone below 100 pg/mL, about 10 ng/dL, also supports a diagnosis of hypogonadism, which is the medical term for testosterone deficiency.^[1]

Other hormones and brain chemicals in the mix

Neurotransmitters are brain chemicals that help nerve cells talk to each other. Systems that use serotonin and norepinephrine appear to be involved in hot flushes, because drugs that modify these systems, such as certain antidepressants, can reduce flush frequency in some men and women. Changes in beta-endorphin, a natural opioid made in the brain, may also alter how the hypothalamus senses body temperature and contributes to the flush response.^[2]

These pathways help explain why non-hormonal medicines like venlafaxine, gabapentin, and clonidine can blunt hot flushes for men on androgen deprivation therapy, even though they do not change testosterone levels.

Conditions linked to it

Not every hot flush in males comes from the same cause. Some triggers are harmless, while others need fast medical attention. These are the most important links to know.

• Age-related testosterone decline and hypogonadism. Many men in their 40s, 50s, and beyond develop low testosterone, especially if they have obesity, type 2 diabetes, or sleep apnea. Low testosterone can cause hot flushes along with fatigue, low sex drive, reduced morning erections, and depressed mood.^[1]
• Androgen deprivation therapy for prostate cancer. Medical castration with GnRH agonists or antagonists, anti-androgens, or surgical removal of the testes is the single most common cause of severe hot flush in males. Up to 80 percent of men on these treatments report bothersome hot flushes and night sweats.
• Removal of a testicle. Orchiectomy, which is removal of one or both testes, may be done for testicular cancer or very advanced prostate cancer. Loss of testicular tissue sharply reduces testosterone and can trigger flushes if the remaining testis cannot compensate.
• Thyroid overactivity. Hyperthyroidism means the thyroid gland in the neck is producing too much thyroid hormone. Symptoms include heat intolerance, flushing, weight loss, tremor, and a racing heart. It can mimic or worsen hot flushes in men.^[3]
• Metabolic and cardiovascular disease. Obesity, high blood pressure, and metabolic syndrome are linked to more frequent night sweats and temperature swings, likely through effects on blood vessels, inflammation, and sleep quality.
• Certain medications and substances. Alcohol, opioids, high dose niacin, and some antidepressants and vasodilators, such as calcium channel blockers, can trigger flushing episodes in susceptible men.
• Less common but serious causes. Cancers such as lymphoma, infections like tuberculosis, and rare hormone-secreting tumors including pheochromocytoma or carcinoid tumors can cause flushing and drenching night sweats. These conditions usually come with other “red flag” symptoms such as unintentional weight loss, fevers, enlarged lymph nodes, or very high blood pressure spikes.^[3]

Most hot flushes in men are linked to testosterone changes or common conditions, but it is important not to assume that is always the case. A doctor’s job is to rule out the dangerous stuff before blaming it all on hormones.

Limitations note: For several of these links, especially metabolic and cardiovascular conditions, evidence comes mainly from observational studies. That means they show associations, not direct cause and effect.

Symptoms and signals

Because many men are not told that hot flushes can happen to them, they often struggle to describe what they feel. Here are common features to watch for.

• A sudden wave of heat starting in the chest, neck, or face, often spreading upward
• Skin that turns red or blotchy during the episode
• Fast heartbeat or feeling “pounded” in the chest
• Medium to heavy sweating, sometimes soaking through shirts or bed sheets
• Chills or feeling cold once the flush passes
• Episodes lasting from 30 seconds up to 10 minutes
• Hot flushes triggered by stress, warm rooms, hot drinks, alcohol, or spicy foods
• Night sweats, which are episodes of sweating that wake you from sleep and require changing clothes or bedding
• Fatigue, brain fog, lower sex drive, or mood changes around the same time that flushes start

You should seek prompt medical care if hot flushes come with any of the following:

• Unintentional weight loss
• Persistent fevers
• New chest pain or trouble breathing
• Very fast or irregular heartbeat
• Swollen lymph nodes, a new lump in the testicle, or bone pain

What to do about it

Dealing with a hot flush in males is not just about cooling tricks. The real goal is to find and treat the cause while easing symptoms so you can sleep, work, and live normally.

1. Get evaluated and tested.

Start with your primary care doctor or a urologist or endocrinologist who is comfortable with male hormone issues.

• Describe your hot flushes in detail, including timing, triggers, and how much they disrupt sleep or daily life.
• Mention all medicines and supplements, including over-the-counter products and testosterone boosters.
• Expect a focused exam that checks weight, blood pressure, thyroid, testes, and prostate as appropriate for your age and history.
• Ask for morning blood tests for total testosterone, and if needed free testosterone, along with luteinizing hormone, follicle-stimulating hormone, thyroid stimulating hormone, complete blood count, and basic metabolic panel.^[1]

In practice, most guidelines suggest that symptomatic men are more likely to benefit from testosterone therapy when total testosterone is consistently below 350 ng/dL or free testosterone is below 100 pg/mL, once other causes are ruled out.^[1] If you are on androgen deprivation therapy, your cancer specialist will already be tracking testosterone, but you should still report hot flushes so they can help manage side effects.

2. Address lifestyle and consider targeted treatments.

For mild to moderate hot flush in males, simple steps can make a noticeable difference:

• Keep bedrooms cool and use breathable bedding and sleepwear.
• Avoid heavy meals, hot drinks, alcohol, and very spicy food near bedtime.
• Lose excess weight if you have overweight or obesity, which can improve both hormones and thermoregulation.
• Prioritize sleep hygiene and address sleep apnea if you snore heavily or stop breathing at night.
• Practice stress management, such as deep breathing, meditation, or regular exercise, since stress can trigger flushes.

When low testosterone is confirmed and no strong contraindications exist, testosterone replacement therapy, often shortened to TRT, can reduce hot flushes in hypogonadal men and improve related symptoms like low libido and fatigue.^[1] TRT is delivered as gels, injections, patches, or pellets. It is usually not appropriate for men with active high-risk prostate cancer or some blood disorders, so decisions must be individualized.

For men on androgen deprivation therapy for prostate cancer, replacing testosterone is usually not an option. In that case, non-hormonal medicines can help:

• Low dose antidepressants such as venlafaxine or paroxetine can cut hot flush frequency by about 50 percent in many men on androgen deprivation therapy.
• Gabapentin, an anti-seizure medicine, can also reduce flushes and improve sleep in some trials.
• Clonidine, a blood pressure medicine, has modest benefit for some patients but may cause dizziness or low blood pressure.
• Progestational agents like medroxyprogesterone acetate or megestrol acetate can be very effective, but they may carry risks for blood clots and weight gain, so they are reserved for severe cases and prescribed with caution.

Non-drug strategies such as paced breathing, acupuncture, and cognitive behavioral therapy show promise for hot flush management, though data in men are still limited and often borrowed from female studies.

Myth vs fact

• Myth: A hot flush in males is “all in your head.”
  Fact: Hot flushes are real physiological events driven by changes in hormones and brain thermoregulation. They show measurable changes in skin temperature, blood flow, and heart rate.^,[2]
• Myth: Only men on prostate cancer treatment get hot flushes.
  Fact: Many men with natural age-related testosterone decline or other hormone issues experience hot flushes, even if they never receive cancer therapy.^,[1]
• Myth: Every man with hot flushes needs testosterone shots.
  Fact: Some men improve with lifestyle changes or non-hormonal medicines. Others should avoid testosterone because of cancer or cardiovascular history. Treatment must fit the cause and the whole man, not just the lab number.^[1]
• Myth: Night sweats always mean cancer or a serious infection.
  Fact: Night sweats can signal serious disease, but in many men they are due to hormone changes, sleep apnea, obesity, or medicines. The key is not to panic, but not to ignore them either.

3. Monitor, adjust, and follow up.

• Track your hot flushes in a simple log, noting time, severity, and possible triggers.
• Recheck testosterone, blood counts, and other labs on the schedule your doctor recommends, especially if you start or adjust TRT or cancer therapy.
• Review your treatment every 6 to 12 months. Life circumstances, cancer status, and cardiovascular risk can change, and your plan should evolve with them.
• Speak up if treatments are not working or side effects are bothering you. There are usually other options to try.

Limitations note: Many studies on hot flush treatments in men are small or adapted from research in women. That means effect sizes and side effect patterns may be less certain. A personalized trial-and-error approach, guided by evidence and safety, is often needed.

Bottom line

A hot flush in males is common, especially with testosterone changes or prostate cancer treatment, and it is not something you just have to “tough out.” Most flushes trace back to a clear physical trigger in the brain’s temperature circuits, the hormone system, or the blood vessels. With proper evaluation, you can rule out dangerous causes, address low testosterone when appropriate, and use both lifestyle and medical tools to dial down the heat. The goal is not perfection, but getting your life and sleep back from those sudden, disruptive waves of heat.

References

1. Bhasin S, Brito JP, Cunningham GR, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. The Journal of clinical endocrinology and metabolism. 2018;103:1715-1744. PMID: 29562364
2. Freedman RR. Physiology of hot flashes. American journal of human biology : the official journal of the Human Biology Council. 2001;13:453-64. PMID: 11400216
3. Vaidya B, Pearce SH. Diagnosis and management of thyrotoxicosis. BMJ (Clinical research ed.). 2014;349:g5128. PMID: 25146390