Summer with endometriosis – why can heat worsen symptoms?

June, July, August. Everyone around you is enjoying the sun, planning trips, and saying that we're finally having the long-awaited summer. Meanwhile, you feel worse than in the middle of winter. The pain is worse, the fatigue is greater, the abdominal bloating persists, and the mere thought of leaving the house in the heat seems unbearable. If you have endometriosis and every vacation feels the same, it's not a coincidence or a matter of a bad mood or grumpiness. High temperatures can actually exacerbate the symptoms of this condition, and this happens for several specific, purely biological reasons.

Heat and Blood Vessels, or the Hidden Mechanism

When the ambient temperature rises dramatically, the body immediately activates thermoregulatory mechanisms. One of these mechanisms is the rapid dilation of blood vessels, particularly in the skin and superficial tissues, which allows for efficient heat transfer. In a healthy person, this is a necessary and safe response. Unfortunately, in women with endometriosis, it has a dark side.

The dilation of blood vessels in the pelvic area can increase congestion in the affected tissues and, consequently, increase local inflammation. Patients most often describe this as a bothersome feeling of heaviness, distention, and pulsation in the lower abdomen, which becomes much more intense than usual on hot days. This is particularly true for women whose endometriosis lesions are located near the large intestine or in the retroperitoneal space, where circulation is richer and the response to thermal stimuli is much more noticeable.

Prostaglandins, inflammation and high fever

Endometriosis maintains a chronic, low-grade inflammation throughout the year. However, heat appears to be an additional factor that can exacerbate this inflammation. High temperatures naturally accelerate cellular metabolism, which can stimulate increased prostaglandin production. These substances are directly responsible for endometriosis pain, painful uterine contractions, and excessive reactivity of surrounding tissues.

This perfectly explains why summer abdominal pain attacks aren't necessarily as clearly linked to a specific phase of the menstrual cycle as they are in the colder months. Severe pain can appear unexpectedly in the middle of a hot week, completely independent of your period, and can be surprisingly intense. The body, already constantly battling underlying inflammation, simply reacts much more strongly and violently to the additional heat stimuli.

Insidious dehydration and its devastating consequences

During the summer months, it's incredibly easy to become dehydrated, especially when we sweat heavily and fluid intake doesn't keep up with losses. In the case of endometriosis, water deficiency has a number of very specific and painful consequences. Primarily, too little fluid thickens the blood, which significantly impedes the efficient removal of inflammatory metabolites from the bloodstream.

At the same time, dehydration drastically worsens constipation, which in endometriosis—especially its intestinal variant—is already a constant, extremely bothersome part of everyday life. Furthermore, a dehydrated body becomes incomparably more susceptible to severe headaches and hormonal migraines, which statistically coexist much more frequently in endometriosis patients than in the general population. This all adds up to a drastic drop in energy and intensified chronic fatigue, which in this disease is rarely associated with actual physical exertion anyway. Just a few hours in the sun without a bottle of water is enough to trigger this painful avalanche of symptoms.

Summer bloating and loose intestines

Many women with endometriosis struggle with digestive symptoms year-round, complaining of "endometriosis," painful bloating, and irregular bowel movements. These symptoms can be more severe in the summer. On the one hand, high temperatures slow down gastrointestinal motility, which promotes prolonged retention and fermentation of intestinal contents.

On the other hand, a vacation diet naturally becomes more chaotic. Eating out more often, reaching for alcohol, ice cream, or sugary sodas instead of balanced, warm meals at home, quickly disrupts the gut microbiome, which is already significantly unstable in endometriosis.

Then there's the mundane yet crucial matter of clothing. In the summer, to look our best, we're more likely to wear fitted clothes, tight shorts, or dresses with elastic waistbands that dig in. For a woman struggling with painful abdominal bloating, this mechanical pressure is an additional source of tension that can trigger a severe bout of pain.

Difficult nights, cortisol and a disturbed pain threshold

Unfortunately, the heat doesn't let up after dark. Hot, muggy nights drastically reduce the quality of sleep, making it shallow and fragmented. A lack of deep rest has a direct, proven impact on our pain threshold – a sleep-deprived body experiences any painful stimulus much more intensely the next day.

In endometriosis, where pain is a near-constant ailment, summer insomnia can drastically lower a woman's overall tolerance for any ailments. To make matters worse, cortisol, our primary stress hormone, is extremely sensitive to any disruption to circadian rhythm. When we lack sleep, morning cortisol levels skyrocket, which immediately increases inflammation and negatively impacts the entire hormonal system. This creates another vicious cycle, which is incredibly easy to fall into during the holidays.

Physical activity on your own terms

Beautiful weather naturally encourages exercise, hikes, and active outdoor activities. Exercise itself is highly recommended and beneficial for endometriosis, but exertion in full sun places a completely different strain on the ailing body than training in comfortable conditions. Intense exercise in high temperatures immediately increases the risk of dehydration and raises core body temperature, which can result in several days of severe pain and exhaustion.

This doesn't mean you should completely give up physical activity in the summer. It's about wisely adapting the form and time of day to the current weather conditions and your body's capabilities. Instead of lying on the beach at high noon, opt for a leisurely walk late in the evening. Instead of demanding runs in the sun, opt for a cooling pool or relaxing yoga in a well-ventilated, shaded room. A body with endometriosis needs exercise in the summer, but above all, it needs exercise with common sense and a great deal of understanding.

How to make the summer months really easier

There are several proven, natural tips that will help you survive the summer heat in much better shape. Adequate hydration becomes an absolute priority during this time. During hot days, fluid requirements significantly exceed the standard two liters of water per day, so it's worth developing the habit of always carrying a bottle with you and taking small sips before you even feel thirsty – remember that a dry mouth is the first warning sign of dehydration.

It's also worth ensuring that your summer diet doesn't rely on heavy snacks from holiday kiosks, whenever possible. Regular meals rich in fresh vegetables, low-glycemic fruit, and a drastic reduction in alcohol and sugar will help keep your intestines in check and minimize bothersome bloating.

You'll also do yourself a huge favor by keeping your bedroom cool. Keeping your windows tightly closed during the day, airing your room late at night, or investing in a good fan is the best protective shield for your sleep, and it will pay off in a higher pain threshold the next morning.

Planning each day wisely, taking into account the weather and your current menstrual cycle, is not a sign of weakness or resignation. It's a mature adaptation of your daily life to real conditions beyond your control. The most important step, however, is internally allowing a much slower pace. You don't have to experience your vacation exactly the same way as your female friends without a diagnosis. You have every right to plan your vacation so that it's dominated by time for regeneration and relaxation in the shade.

Your summer, your pace

Endometriosis, unfortunately, doesn't take a vacation in July or August. For many women, summer is paradoxically the most difficult season of the year, mainly due to the stark and painful contrast between society's expectation of eternal joy and how they actually feel. While everyone around them is celebrating and partying until dawn, you may be waging a silent, exhausting battle with pain, fatigue, and "endo belly" at 30 degrees in the shade.

If you've noticed this recurring pattern over the years, be sure to mention it at your next visit to your doctor. Seasonal, significant worsening of symptoms due to weather is crucial clinical information, not a whim. Understanding why your body reacts this way is a crucial first step to making each subsequent summer a little more bearable for you.

Sources

• Vercellini P. et al. Endometriosis: pathogenesis and treatment. Nature Reviews Endocrinology, 2014.
• Koninckx PR et al. Endometriosis, a contested disease: The role of systemic low-grade inflammation. Facts, Views and Vision in ObGyn, 2023.
• Mowers EL et al. Prevalence of endometriosis during abdominal or laparoscopic hysterectomy for chronic pelvic pain. Obstetrics and Gynecology, 2016.
• Coxon L. et al. What is dysmenorrhea, how does it affect women and what treatments are available? Pain, 2020.
• ESHRE Endometriosis Guideline Development Group. Endometriosis: guideline of the European Society of Human Reproduction and Embryology. ESHRE, 2022.