Nausea, a common and uncomfortable sensation, can impact daily life. While many factors contribute to feelings of sickness, the body’s endocrine system often plays a role. This system, a network of glands that produce and release hormones, influences physiological processes like digestion and overall well-being. Understanding how these chemical messengers affect nausea provides insight into this symptom.
How Hormones Trigger Nausea
Hormones can trigger nausea by influencing specific brain areas and the digestive tract. The chemoreceptor trigger zone (CTZ) in the medulla oblongata receives signals from the bloodstream and communicates with the brain’s vomiting center. Neurotransmitters like serotonin and dopamine are involved, and hormonal fluctuations can alter their balance, leading to sickness. Hormones also directly impact gut motility, the movement of food through the digestive system. Estrogen and progesterone, for instance, can affect digestive tract muscles, potentially slowing digestion and contributing to nausea.
Nausea During Pregnancy
Nausea and vomiting during pregnancy, often called “morning sickness,” is a common experience, affecting up to 80% of pregnant individuals in the first trimester. This symptom is linked to the rapid increase in hormones essential for maintaining pregnancy. Human chorionic gonadotropin (hCG) levels rise during early pregnancy and are implicated in causing nausea, with symptoms often peaking when hCG levels are highest, around 9-12 weeks. Estrogen and progesterone also increase during pregnancy and contribute to digestive discomfort. These hormonal shifts can affect the digestive system, potentially slowing gut motility, and influencing the brain’s vomit center, leading to feelings of sickness. While challenging, mild morning sickness is sometimes considered a sign of a healthy pregnancy.
Menstrual Cycle and Nausea
Fluctuations in estrogen and progesterone throughout the menstrual cycle can lead to nausea. Before menstruation, during the luteal phase, both estrogen and progesterone levels rise and then decline if pregnancy does not occur. This drop in hormones, especially estrogen, can influence neurotransmitters like serotonin, which plays a role in mood regulation and can contribute to premenstrual syndrome (PMS) symptoms, including nausea. Progesterone can slow digestion, contributing to nausea during this phase. Some individuals may notice these symptoms around ovulation or as part of PMS.
Other Hormonal Influences on Nausea
Hormonal changes beyond pregnancy and the menstrual cycle can contribute to nausea.
Perimenopause and Menopause
During perimenopause and menopause, declining and fluctuating estrogen levels can affect digestion, leading to symptoms like bloating, indigestion, and nausea. These hormonal shifts can also influence the brain’s vomiting center.
Thyroid Imbalances
Thyroid imbalances, both hyperthyroidism and hypothyroidism, can impact gastrointestinal function and metabolism, resulting in nausea. Hyperthyroidism can speed up intestinal movement, while hypothyroidism can delay digestion, both causing digestive discomfort.
Hormonal Birth Control
Synthetic hormones in birth control can also cause nausea, especially when first starting or changing methods, as the body adjusts. This side effect usually subsides within a few months.
Stress
Additionally, chronic stress elevates hormones like cortisol and adrenaline, which can disrupt gut function and lead to nausea by affecting blood flow and the gut microbiome.
When to Seek Medical Advice
While hormonally induced nausea is often manageable, certain symptoms warrant medical evaluation. Seek prompt medical attention if nausea is accompanied by severe abdominal pain, high fever, stiff neck, or confusion. Other concerning signs include persistent vomiting lasting more than two days in adults, signs of severe dehydration like extreme thirst or infrequent urination, or unexplained weight loss. Additionally, if vomit contains blood, resembles coffee grounds, or is green, or if nausea interferes with daily life, consult a healthcare professional. This information is for educational purposes only and should not replace professional medical advice.