Associations between endometriosis and common symptoms: findings from the Australian Longitudinal Study on Women’s Health

BACKGROUND: Endometriosis has been linked to higher rates of a variety of symptoms; however, the findings from longitudinal studies are scarce and inconsistent. OBJECTIVE: This study aimed to examine the association between endometriosis and common symptoms in a prospective cohort study. STUDY DESIGN: This study included 7606 women born from 1973 to 1978 using data from the Australian Longitudinal Study on Women's Health that were collected every 3 years from 2009 to 2018. We identified women with endometriosis based on self-reported incidence from each survey and linked administrative health data. At each survey, women also completed a checklist on the presence of 24 symptoms. Generalized estimating equations for multinomial responses were used for analyses. RESULTS: Women with endometriosis had significantly more menstrual symptoms than those without endometriosis with an adjusted odds ratio (95% confidence interval) of 3.61 (3.11-4.19) for severe period pain, 2.40 (2.10-2.74) for heavy menstrual bleeding, 1.76 (1.52-2.03) for irregular bleeding, and 1.52 (1.32-1.76) for premenstrual tension. They also had higher odds of mental health problems with adjusted odds ratios of 1.67 (1.39-2.01) for depression and 1.59 (1.24-2.03) for anxiety and higher odds of allergies and nonspecific symptoms with adjusted odds of 1.62 (1.40-1.89) for allergies or hay fever or sinusitis, 1.79 (1.56-2.05) for severe tiredness, 1.56 (1.35-1.81) for sleep difficulty, and 1.77 (1.37-2.18) for palpitations. There was also a strong association with other forms of pain with an adjusted odds ratio of 1.76 (1.53-2.04) for backpain, 1.50 (1.29-1.74) for headaches or migraines, and 1.65 (1.41-1.93) for stiff or painful joints. Women with endometriosis also had increased odds of developing bowel and urinary symptoms with an adjusted odds ratio (95% confidence interval) of 1.67 (1.35-2.08) for constipation, 1.46 (1.12-1.90) for hemorrhoids or piles, 1.25 (1.03-1.52) for indigestion or heartburn, 2.80 (1.71-4.58) for urine burn or stings, and 1.37 (1.03-1.82) for vaginal discharge or irritation. The association between each symptom and endometriosis was similar whether endometriosis was surgically confirmed or clinically suspected. No association was found between endometriosis and the risk for skin problems, leaking urine, or breathing difficulty. CONCLUSION: This study suggests that women with endometriosis are more likely to report not only menstrual symptoms but are also at an increased risk for mental health problems, other pain symptoms, bowel and urinary symptoms, and nonspecific symptoms, such as severe tiredness and difficulty sleeping.