Typically veins are generally wider than arteries, and therefore the pressure is lower. Capillaries are tiny vessels, so repsent high resistance to the incoming blood, so the rate of blood flow through will be quite low. All blood from the artery eventually passes through capillaries and into the vein.
Other causes of an overactive thyroid can include inflammation of the thyroid due to viruses or bacterial infections. Also, postpartum hyperthyroidism affects women immediately after pregnancy. This is one of the most common postpartum health disorders, and it affects between ten and twenty percent of women.
A common cause of overactive thyroid in pregnant women is Gravesâ disease. This disease occurs when your immune system becomes overactive and forms antibodies (immune proteins) that attack the thyroid. This causes the gland to enlarge and make too much thyroid hormone. Most women with Gravesâ disease find out they have it and get treatment before they become pregnant. Women with severe nausea and vomiting or those expecting twins may develop temporary hyperthyroidism.