Why do some diseases affect women more than men and vice versa? Does it all come down to genetic and biological differences, or is there more at play?
All over the world, life expectancy is currently lower in men than women, yet women are more likely to suffer from physical illness.
If we look at the presence of diseases or pathologies around the globe, we will see clear differences in health needs. Various studies have shown that differences in health outcomes are affected by epidemiological and social circumstances, as well as changes in behaviors, which explains why some diseases are more common in certain parts of the world. These factors also influence the differences in health conditions between men and women.
Women’s health: still an unknown subject
When we talk about women’s health, we automatically think about gynecological concerns, or conditions that are unique to women due to their anatomy, such as endometriosis, ovarian cysts, pregnancy, ovarian or cervical cancer, or menopause. And while these are important conditions to keep in mind, women’s health encompasses much more than that. It is defined by the NIH National Library of Medicine as “the branch of medicine that focuses on the treatment and diagnosis of diseases and conditions that affect a woman’s physical and emotional well-being”.
So why differentiate between men and women’s health? Because, while some diseases are common for both groups, their impact can vary between these. Some pathologies are prevalent in men, others in women, and depending on the case, they can present different symptoms and even evolve differently.
Since including women as volunteers in research was not required until recent years, many of these differences between male and female are unknown or have not been studied. This has led to healthcare systems not being tailored to women’s needs, and difficulties in diagnosing or identifying certain conditions in the female population.
Heart attacks are a classic example of this. If someone were to ask you what the symptoms of a heart attack are, you would probably answer chest pain, and pain in the arm or shoulder. You would be correct; these are some of the most common symptoms, but mainly in men. Indigestion, nausea, vomiting, shortness of breath and backpain are all also symptoms that women can experience, when having a heart attack, and yet most people do not know they are related.
Most common female health problems
- Endometriosis is a benign, female-specific medical condition where endometrial tissue grows outside of the uterus, forming lesions. The endometrium is the inner lining of the uterus, the tissue that grows during the menstrual cycle and then sheds, becoming menstrual blood.
While the cause of endometriosis is still unknown, estimates show it affects around 10% of women worldwide. Its symptoms include pelvic pain, heavy menstrual bleeding, menstrual irregularities, pain during sexual intercourse, and possible fertility issues. The severity of symptoms varies, and diagnosis usually involves imaging techniques such as ultrasound or MRI, and even surgical techniques like laparoscopy to be able to identify the lesions, how many there are, where they are, and how deep they are. Treatment of endometriosis revolves around pain management, suppressing endometrial growth, and in some cases, removal of the lesions.
Aside from those conditions that are unique to women, such as endometriosis, there are many other diseases that occur in both men and women but are more common in women.
- Migraines are intense headaches that are described as a pulsating or throbbing pain, that is sometimes made worse by physical activity, bright light, or loud noises. The pain is often severe and incapacitating, lasting from several hours to even days. Migraines affect around 18% of women, who are 3 times more likely to suffer from migraines than men. Many things have been identified to trigger migraines, such as lack of sleep, changes in weather, alcohol, caffeine, and estrogen. Estrogen being a trigger might explain why these are more common in women.
- Depression is a disorder that interferes with daily functioning, and is characterized by an intense feeling of sadness, a decrease in interest in or pleasure gained by activities. It is often accompanied by tiredness, irritability, and anxiety, as well as changes in sleep patterns. Depression affects 5% of adults and up to 1 in 6 older adults, and although the exact cause is unknown, many factors are known to increase the risk of developing depression, such as family history of depression, emotionally distressing life events, the presence of certain medical disorders. Depression is also 50% more common in women, although the reason why this is, is unknown.
Some conditions are more prevalent in women due to the female anatomy or lifecycle, such as:
- Cystitis is a type of Urinary Tract Infection (UTI), known as a lower UTI. UTIs are infections of the urinary tract at any level, and cystitis specifically refers to an infection of the bladder and is usually caused by bacteria. The most common symptoms are a frequent need to urinate, and pain or burning sensation during urination. Contrary to popular belief, men can get cystitis, but the female anatomy makes this condition more likely in women. How? Well, the bladder is usually a sterile organ, and for it to become infected, bacteria need to travel up the urethra to get to the bladder. Women have a shorter urethra than men, and it is located near areas that tend to have bacteria, the vagina, and the anus. In other words, it more likely and easier for bacteria to make its way to the urethra and bladder, causing more infections in women.
- Osteoporosis is a degenerative bone disease, where there is a decrease in bone density, making them weaker and more prone to fractures. At 30-35 years of age, a person reaches the peak of their bone health. After this age, the creation of new bone lessens and naturally the amount of bone in the body reduces over time. When too much bone mass is lost, it can lead to osteoporosis. Sex hormones, among other factors, play an important role in promoting the creation of new bone. As a result of menopause (which is when sex hormone levels begin to decline in women), bone loss is accelerated in women over the age of 50 in comparison to men, making osteoporosis more likely in women.
- Breast cancer is a malignant disease caused by cells in the breast becoming abnormal and dividing uncontrollably to form a tumor. This is one of the most common types of cancer in women, but it is not a female-only disease. Although breast cancer is about 100 times more frequent in women, men can also develop breast cancer. The basic anatomy of the male and female breast is very similar, and the same types of cells are present. However, during puberty, a woman’s breast will develop working lobules and milk ducts, which is where most breast cancers in women occur, while men mainly have fibrous tissue, and fewer ducts and lobules. The fact that women produce higher levels of estrogen, might also contribute to the appearance of breast cancer.
Most common autoimmune disease in females
Autoimmune disorders are caused by an error in the body’s immune system that makes it attack its own tissues and organs. Our immune system normally protects us against infections and harmful external agents. It is specialized in identifying these dangerous substances, by firstly recognizing if it is part of the body, or foreign to it, as well as if it is dangerous or not before attacking. When this system fails, the body sees parts of itself as foreign and attacks them. The causes of these disorders are still unclear but, it is believed that sex hormones might play a role. Estrogen for example has shown to heighten a person’s immune response, which could explain why women are 4 times more likely to develop autoimmune disorders than men.
- Multiple Sclerosis (MS) is an autoimmune disease that affects the brain, spinal cord, and optic nerves. Although the exact root of MS is unknown, it is believed to be caused by an autoimmune reaction that targets a person’s nerves, specifically, the patches of myelin. Most nerves in the human body are covered by a substance called myelin, which allows nerve signals to move faster along the nerve. When the patches of myelin are damaged or destroyed, the nerve fibers under it can also be affected. MS is a degenerative disease that can begin at any time between the ages of 15 and 60, and it is uncommon for children to develop it. Because of the nerve damage caused by MS, it is usually accompanied by sensory or motor symptoms, such as tingling, loss of strength or dexterity; with fluctuation periods of improvement and worsening, as well as vision problems. Studies have shown that while women are 3 to 4 times more likely to develop MS, they mainly suffer from a form of the disease known as relapsing-remitting MS (RRMS), involving periods of flare-ups or relapses of new or worsening of symptoms. Men on the other hand, are more likely to live with a progressive stage of MS (secondary-progressive or primary-progressive MS), which involves a gradual progression and accumulation of disability with or without the relapses.
- Rheumatoid Arthritis (RA) is also an autoimmune disease, and affects 1% of the world’s population, where the joints and connective tissue are targeted, causing inflammation, pain, and stiffness. Smaller joints are more commonly affected, like those in the hands and feet. The exact cause of rheumatoid arthritis is unknown, but the damage to the joints results in deterioration, deformity, and instability of the joints. It is thought that the reason why women are 3 times more likely to develop RA is due to many factors, such as sex hormones, environmental triggers, and gender-based roles in society. Women also tend to present a more aggressive disease, with higher chance of disability than men.
Although women have historically been excluded from studies of common pathologies, and funding is lower for research in conditions that predominantly affect women, the concept of global health is becoming more and more popular. We still have a long way to go, but we are increasingly aware of the differences in health, and that women are more commonly affected by disabling or chronic diseases than men. Inclusive research is necessary for society to advance and is gradually taking on a more relevant role in scientific and medical institutions, as well as healthcare.