Can Hormones Cause Hemorrhoids? Explaining the Connection

Hormones do not single-handedly cause hemorrhoids, but they are genuine contributors. Several hormones, especially progesterone and estrogen, affect the tone and elasticity of vein walls throughout the body, including the vessels in and around the rectum. When hormonal shifts loosen those walls or promote constipation, the conditions for hemorrhoids improve considerably. The link is clearest during pregnancy, but it extends to thyroid disorders, the menstrual cycle, and even hormone-based medications.

How Hormones Weaken Vein Walls

Hemorrhoids are essentially swollen, inflamed veins in the lower rectum or around the anus. Anything that increases pressure on those veins or weakens the vessel walls makes them more likely to bulge and cause symptoms. Hormones enter the picture because sex hormones directly influence vascular smooth muscle, the layer of tissue that gives veins their ability to contract and maintain shape.

Progesterone, in particular, relaxes smooth muscle. That is biologically useful in pregnancy, where the uterus needs to stay flexible and blood flow to the fetus needs to increase. But the effect is not confined to the uterus. Progesterone circulates throughout the body and relaxes veins everywhere, including the hemorrhoidal plexus. Research on sex hormones and vascular tone has shown that these hormones inhibit the signaling mechanisms that normally keep vascular smooth muscle contracted, including intracellular calcium pathways and protein kinase C activity.¹ The result is veins that are wider, more compliant, and less able to push blood efficiently back toward the heart.

Estrogen plays a related but somewhat different role. It tends to stimulate nitric oxide production in the endothelium, the inner lining of blood vessels, which also promotes relaxation. Together, estrogen and progesterone create a hormonal environment where veins dilate more easily and have reduced capacity to handle back-pressure. In the rectal area, where gravity already works against venous return, that combination can tip otherwise healthy vessels into symptomatic hemorrhoids.

Pregnancy and the Strongest Hormonal Link

If there is one life stage where the hormone-hemorrhoid connection is hard to miss, it is pregnancy. Progesterone levels climb dramatically from the first trimester onward, peaking in the third trimester at levels many times higher than in a non-pregnant woman. At the same time, the growing uterus physically compresses the inferior vena cava and pelvic veins, raising venous pressure in the lower body. These two forces, hormonal vein relaxation and mechanical compression, converge on the same vulnerable vessels.

A large systematic review and meta-analysis pooling data across 21 studies found that the overall prevalence of hemorrhoids is slightly higher in women than in men, about 27% in women compared to roughly 26% in men. The authors attributed this gap in part to physiological and hormonal factors, particularly pregnancy, which increases intra-abdominal pressure and induces vascular changes that promote hemorrhoid development.² That gender difference was consistent across all timeframes measured, suggesting it is not just a snapshot during childbearing years but a persistent pattern.

Beyond pregnancy itself, childbirth adds its own contribution. The CHORUS study, a large evaluation of hemorrhoidal disease and chronic venous insufficiency, found that among women, the number of births was significantly associated with both hemorrhoid severity and recurrence.³ Each pregnancy compounds the damage. The prolonged straining of vaginal delivery can stretch and weaken the pelvic floor muscles that help support rectal veins, while the months of elevated progesterone soften those veins from the inside. Women who have had multiple pregnancies carry a measurably higher burden.

Thyroid Hormones and the Constipation Route

Hormones do not have to act directly on veins to promote hemorrhoids. They can also get there indirectly, by changing how your gut moves. The clearest example is hypothyroidism, where the thyroid gland produces too little thyroid hormone. One of the most common complaints in hypothyroidism is chronic constipation, and constipation is one of the strongest and best-established risk factors for hemorrhoids.

When thyroid hormone levels are low, gastrointestinal motility slows down. Food and waste take longer to transit through the intestines, stool becomes harder, and the urge to strain on the toilet increases. Research into constipation management in hypothyroidism has described how the condition slows gastrointestinal movement through neuromuscular dysfunction, hormonal resistance, and structural changes in the intestinal wall itself, including thickening of the muscular layer and shortening of intestinal villi.⁴ The straining that results from this chronic constipation pushes blood into the hemorrhoidal veins and prevents it from draining, eventually causing the vessels to enlarge.

This means that if you have an underactive thyroid and are dealing with persistent hemorrhoids, treating only the hemorrhoids without addressing the thyroid problem is fighting a losing battle. Getting thyroid levels properly managed often improves bowel regularity, which reduces the straining that keeps hemorrhoids coming back. It is one of those situations where the hemorrhoids are really a downstream symptom of a hormonal imbalance happening somewhere else entirely.

Menstrual Cycle Fluctuations

Many women report that hemorrhoid symptoms flare in the days leading up to their period, then ease once menstruation begins. This pattern is not widely studied in controlled trials, but it makes physiological sense. In the luteal phase, the roughly two weeks between ovulation and the start of a period, progesterone levels are at their monthly peak. As discussed earlier, progesterone relaxes vein walls. So the same mechanism at work during pregnancy operates in a smaller, cyclical way every month.

On top of the vascular effects, the luteal phase is also when many women experience bloating, water retention, and slower bowel transit. Progesterone slows gut motility just as it slows other smooth muscle contractions, meaning the same hormone that relaxes rectal veins also makes you more likely to be constipated. The combination of softer vein walls and harder stools is a recipe for flares.

For women who notice this pattern, timing matters. Increasing fiber intake and staying well hydrated in the second half of the menstrual cycle can offset some of the progesterone-driven slowdown. A stool softener during those days is another practical option. The goal is to keep stool soft enough that you do not have to strain, even when your hormones are working against you.

When Rectal Endometriosis Gets Mistaken for Hemorrhoids

There is another hormone-related condition that deserves mention here, not because it causes hemorrhoids but because it convincingly imitates them. Endometriosis occurs when tissue similar to the uterine lining grows in places it should not, and one of those places can be the rectum. Rectal endometriosis responds to the same monthly hormonal fluctuations as the uterine lining, swelling and sometimes bleeding in sync with the menstrual cycle.

The symptoms of rectal endometriosis, including rectal pain and blood in the stool, overlap significantly with hemorrhoid symptoms. When a patient has both conditions, the endometriosis can easily be overlooked because the symptoms are attributed entirely to the more common hemorrhoids, especially if the endometriotic nodule is small and located deep under the rectal mucosa.⁵ This matters because the treatments are completely different. Hemorrhoid creams and dietary changes will not touch endometriosis; that condition often requires hormonal suppression therapy or surgery.

A useful clue is timing. If your rectal symptoms are closely tied to your menstrual cycle, worsening predictably in the days just before or during your period and then fading, that cyclical pattern should raise the question of endometriosis alongside hemorrhoids. Mentioning the timing pattern to a doctor can be the difference between a quick diagnosis and years of treating the wrong condition.

Hormone Medications and External Hormones

Hormonal contraceptives, hormone replacement therapy, and testosterone supplementation all alter your baseline hormone levels, and in theory, they could influence hemorrhoid risk. Combined oral contraceptives deliver synthetic estrogen and progesterone, which means women on the pill experience some degree of the same vein-relaxing effects seen in pregnancy, just at much lower doses. Whether this translates into a clinically meaningful increase in hemorrhoid risk is not well established. The hormonal doses in modern contraceptives are low enough that the effect on large veins tends to be modest compared to pregnancy.

Hormone replacement therapy in postmenopausal women reintroduces estrogen and sometimes progesterone. There is some theoretical concern that this could soften vein walls, but the evidence specifically linking HRT to hemorrhoid development is thin. Where HRT seems to matter more is in the broader context of chronic venous insufficiency, which involves the same kind of venous valve failure and dilation that underlies hemorrhoids. The CHORUS study found a strong connection between hemorrhoidal disease and chronic venous insufficiency in the legs, suggesting they share underlying vascular mechanisms.³ If hormone therapy is contributing to varicose veins or venous insufficiency in your legs, the same process could be affecting rectal veins.

Testosterone therapy, used increasingly for low testosterone in men and sometimes in transgender hormone therapy, has its own indirect route. Testosterone can increase red blood cell production, which thickens the blood and may increase venous pressure. It can also contribute to constipation in some users. Neither of these effects is dramatic enough to make testosterone a primary cause of hemorrhoids, but in someone already prone to them, it could tip the balance.

Stress Hormones and the Gut

Cortisol, the body’s main stress hormone, is not typically discussed in the same breath as hemorrhoids, but it connects through two pathways. First, chronic stress and elevated cortisol alter gut motility. Some people develop diarrhea under stress, others constipation, and both extremes can aggravate hemorrhoids. Frequent loose stools irritate the anal lining, while constipation leads to straining. Second, cortisol suppresses immune function and slows tissue repair, which means that if you already have hemorrhoids, chronic stress may make them slower to heal and more prone to inflammation.

The gut-brain connection is well established. Stress changes the signals traveling along the vagus nerve, alters gut microbiome composition, and shifts the balance of fluid secretion in the intestines. None of this makes cortisol a direct cause of hemorrhoids in the way progesterone is, but it can create a chronic background of digestive disruption that makes hemorrhoids more likely to develop and harder to resolve. People who notice their hemorrhoid symptoms worsen during high-stress periods are not imagining it.

Treatments That Target Vein Tone

If hormones contribute to hemorrhoids partly by weakening vein walls, then strengthening those walls should help. That is the rationale behind phlebotonics, a class of drugs (often plant-derived) that improve venous tone and reduce capillary fragility. A Cochrane review of the evidence found that phlebotonics produced significant improvements across multiple hemorrhoid symptoms: bleeding dropped substantially, itching improved, discharge and leakage decreased, and overall symptom scores improved markedly compared to controls.⁶ The same review found benefits for post-surgical bleeding after hemorrhoid removal.

Phlebotonics include compounds like diosmin, hesperidin, and rutosides, which are available as supplements in many countries and as prescription drugs in others. They work by tightening the walls of veins and improving lymphatic drainage, essentially counteracting the vein-loosening effect that progesterone and estrogen produce. For people whose hemorrhoids seem tied to hormonal states, these agents offer a targeted approach that goes beyond the standard advice of fiber and sitz baths.

That said, phlebotonics are not a substitute for addressing the root hormonal or mechanical cause. If pregnancy is the trigger, the hormonal component will resolve after delivery, though the structural damage may not. If hypothyroidism is driving constipation, thyroid treatment is the real fix. Phlebotonics work best as an adjunct, helping to manage symptoms while the underlying hormonal situation is either treated or runs its course.

Why Hemorrhoids Are Not Purely a Hormonal Problem

It would be an overstatement to call hemorrhoids a hormonal disease. Hormones are one thread in a web that includes diet, physical activity, time spent sitting, straining habits, genetics, and aging. Plenty of people with perfectly normal hormone levels develop hemorrhoids, and plenty of people with significant hormonal shifts never do. What the evidence shows is that hormones modulate the risk, sometimes significantly, by affecting vein wall integrity and bowel habits.

The practical takeaway is that if your hemorrhoids seem to follow a hormonal pattern, whether that means flares before your period, new onset during pregnancy, or chronic problems that started when your thyroid went off, treating the hemorrhoids without acknowledging the hormonal component leaves you chasing symptoms. Conversely, if you are starting a hormonal medication and have a history of hemorrhoids, being proactive about fiber, hydration, and possibly phlebotonics is a reasonable strategy. The veins in your rectum respond to the same hormonal signals as veins everywhere else in your body. They just happen to be in a spot where gravity, pressure, and daily mechanical stress make the consequences harder to ignore.