Nausea is one of the most common symptoms of hundreds of diseases and conditions. It can vary in severity from a minor ache to stomach-wrenching pain. Medically, it is important to note the distinction between nausea and vomiting, because many people associate the two symptoms. Nausea is specifically the uneasiness a person feels in their stomach that accompanies an urge to vomit, but it does not describe the ejection of matter from the stomach.
Pregnancy
One of the most common causes of nausea is pregnancy. Often, women in the first trimester experience both nausea and vomiting. Many people would recognize this as “morning sickness.” Despite its name, pregnant women are capable of feeling nauseated at any point in the day. Between 25 and 55% of pregnant women deal with vomiting alongside nausea, though the symptoms are not usually severe. In rare instances, a pregnant woman may become dehydrated after prolonged periods of vomiting.
Anesthesia
Some people experience nausea after receiving a general anesthetic. Doctors use general anesthesia on patients before surgery or other medical procedures. While under the influence of an anesthetic, the patient feels no pain because their brain cannot respond to pain signals or reflexes. Once the patient wakes up, they may experience a variety of side effects, including dry mouth, sore throat, itching, shivering, and fatigue. Of course, they may also have some feeling of nausea.
Migraines
Migraines are significantly worse than the average headache. Usually, they affect only one side of the head and cause a severe throbbing or pulsing pain. Migraines often cause extreme sensitivity to light and sound. In some cases, severe migraines prompt both nausea and vomiting. The worst migraines can last days and are so painful that the person experiencing the migraine is more or less incapable of performing most actions.
Motion Sickness
Motion sickness makes people feel discomfited when they’re in ships, cars, planes, or other modes of transportation. They may feel just a vague uneasiness, but the symptoms can progress to nausea and vomiting. The transient condition occurs due to disturbances of the inner ear, which is responsible for equilibrium and balance. The brain receives conflicting information about the body’s position and the motion it is experiencing through not only the ears, but also the eyes, skin receptors, muscles, and joint sensors.
Stomach Conditions
A wide variety of stomach conditions can result in nausea:
- Gastroenteritis or stomach flu is one of the most common issues. Despite its name, it is unrelated to influenza. Viral, bacterial, or parasitic infections can be responsible for gastroenteritis.
- Gastroparesis features issues with the nerves or muscles in the stomach, which slow the process of digestion and stomach emptying.
- Gastroesophageal reflux disease (GERD) occurs when stomach acid backs up into the esophagus. GERD has a number of symptoms, and nausea is common.
Intestinal Obstructions
Some diseases create obstructions in the intestines that can consist of fibrous tissue, inflammation, or infected tissue pouches. Because of the blockages, food and liquid struggle to pass through. This can cause symptoms that range from mild nausea to extreme pain, and severe cases can cause tissue death. Despite the seriousness of the issue, intestinal obstructions are fairly simple to resolve once diagnosed. The key symptom that hints at an obstruction is the inability to have a bowel movement or pass gas.
Chemotherapy
Because cancer cells multiply and grow faster than most other cells in the body, one of the most effective treatments is chemotherapy. In chemo treatments, powerful chemicals kill the fast-growing cells in the body. Unfortunately, people undergoing chemotherapy deal with a variety of side effects, the most common of which are nausea, vomiting, hair loss, fatigue, fever, and pain.
Stress and Fear
Though it may seem odd, it doesn’t take a physical illness to create nausea. Many people experience nausea when they’re feeling high levels of stress, fear, or dread. Individuals with anxiety, panic, or mood disorders may have chronic nausea. Stress, fear, and anxiety can trigger the body’s fight or flight response which, in turn, affects almost every system of the body. In the digestive system, nausea, vomiting, heartburn, diarrhea, and constipation can result.
Appendicitis
A small, tubular organ connects to the first section of the large intestine. This tube-like organ is the appendix, and it’s one of medicine’s great mysteries. Experts do not fully understand the appendix’s functions. It is primarily remarked upon when problematic: inflammation of the appendix causes appendicitis. People with the condition often first experience nausea, and eventually feel extreme pain. Most cases of appendicitis require removal of the organ. Without treatment, the appendix may burst, which leads to sepsis.
Brain Conditions
Because the brain is the control center of the body, the conditions and diseases that affect it are often complex. A general condition that leads to nausea is autonomic dysfunction, which occurs when the autonomic nervous system (ANS) fails to operate properly. The ANS maintains physical well-being and general health. Its responsibilities include digestion, sweating, heart rate control, and much more. Other issues, such as brain tumors, have many different effects depending on their location and size. For example, a tumor may interrupt the signals from the inner ear to the brain or interfere with the signals responsible for digestion, both of which can cause nausea.