Sex Differences In Medicine

Sex differences in medicine include sex-specific diseases or conditions which occur only in people of one sex (for example, prostate cancer in males or uterine cancer in females); sex-related diseases, which are diseases that are more common to one sex (for example, systemic lupus erythematosus occurs predominantly in females); and diseases which occur at similar rates in males and females but manifest differently according to sex (for example, peripheral artery disease). Sex differences in medicine should not be confused with gender differences. The US National Academy of Medicine recognizes sex differences as biological at the chromosomal level, whereas gender differences are based on self-representation and other factors including biology, environment and experience. Sex differences in medicine should also not be confused with sexually transmitted diseases, which are diseases that have a significant probability of transmission through sexual contact.

Historically, medical research has primarily been conducted using the male body as the basis for clinical studies. The findings of these studies have often been applied across the sexes and healthcare providers have traditionally assumed a uniform approach in treating both male and female patients. More recently, medical research has started to understand the importance of taking sex into account as evidence increases that the symptoms and responses to medical treatment may be very different between sexes.

Sex-related illnesses have various causes:

• Sex-linked genetic conditions
• Diseases of the reproductive system that are specific to one sex
• Social causes that relate to the gender role expected of that sex in a particular society
• Different levels of prevention, reporting, diagnosis or treatment in each gender.

Women

Examples of sex-related illnesses and disorders in female humans:

• 99% of breast cancer occurs in women.
• Ovarian cancer, endometriosis and other diseases of the female reproductive system occur only in women.
• Approximately four times more women suffer from osteoporosis than men.
• Autoimmune diseases, such as Sjögren's syndrome and scleroderma, are more prevalent in women. Roughly 70 percent of those living with autoimmune diseases are female. See Sex differences in autoimmunity.
• In Western cultures, almost ten times more women than men suffer from eating disorders such as anorexia nervosa and bulimia nervosa.
• Alzheimer's disease has a higher rate in women than in men.
• About two times more women than men suffer from unipolar clinical depression (although bipolar disorder appears to affect both sexes equally).
• About three times more women than men are diagnosed with borderline or histrionic personality disorder.
• Conditions such as chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME), postural orthostatic tachycardia syndrome (POTS), fibromyalgia, irritable bowel syndrome (IBS) and idiopathic hypersomnia, which have unclear causes, are more common in women, with sex ratios ranging from 2:1 in IBS, fibromyalgia and idiopathic hypersomnia to 4:1 in CFS and 5:1 in POTS.
• Most people with psychogenic non-epileptic seizures (PNES) (75%) are women.

Men

Examples of sex-related illnesses and disorders in male humans:

• Prostate cancer and other diseases of the male reproductive system occur only in men.
• Diseases of X-linked recessive inheritance, such as colour blindness, occur more frequently in men, and haemophilia A and B occur almost exclusively in men.
• Abdominal aortic aneurysms are six times more common in men, and thus some countries have introduced screening for males at risk of suffering the condition.
• Autism is approximately 4 times more prevalent in males than females.
• Schizophrenia is about 1.4 times more common in males and on average starts 2 years earlier and has more severe symptoms.
• More than two times more men than women are affected by antisocial personality disorder and substance use disorder.
• Several cancers, including stomach cancer (2:1), oesophageal cancer (3:1), liver cancer (2:1 to 4:1) and oral cancer (2:1 to 3:1), which have mostly lifestyle-based risk factors, are more common in men.

See also

• Andrology
• Health equity
• Men's health
• Obstetrics and gynecology
• Reproductive medicine
• Sex differences in humans
• Women's health