Why does chronic pain cause nausea and vomiting?

Nausea is a particularly nasty symptom. Your stomach’s on a rollercoaster and you’re sure you’re going to throw up. It can occur as a precursor to vomiting, or on its own. But for someone with chronic pain, nausea can be part of everyday life.

There are generally two causes of nausea when you have a chronic illness. One is connected to the disease itself, where living with extreme chronic pain includes symptoms of nausea. This can happen whenever your pain gets too high or you are exhausted from no sleep. It is unpredictable. The other is as a side effect of the treatment for your chronic illness. When you have a chronic illness, you often have to take a lot of medication, much of which can make you nauseated. It can be hard to balance the potential side effects against the beneficial effects of the medication.

Nausea is what is called a non-specific symptom, which means that a variety of ailments can cause it to appear. Vomiting is controlled by the autonomic nervous system (ANS) in our brains,. So nausea is basically controlled unconsciously and involuntarily.

When you are in an extreme amount of pain, your nervous system lights up and your body starts to mobilize a pain response. The most common type of pain, nociceptive, is the result of nerve fibers being subjected to a stimulus that exceeds its "safe" intensity. Nociceptive pain can be divided into a few categories but the one which causes nausea is usually visceral pain.

Visceral pain is most commonly described as pain that feels deep, distant, systemic, and sickening. It commonly causes nausea because this type of pain makes your whole body feel "off". Also, since you are in severe pain, you are most likely being subjected to shock. Your sympathetic nervous system plays a role in this as well by causing organs such as the adrenal glands to release hormones. This can subsequently raise your heart rate, blood pressure and respiration rates.

THe reason for the nausea is a biological response. If you are in intense pain and your nervous system is in a hyperactive state, while hormones are changing your basic system responses — BP, HR, etc. — it leads to a feeling of nausea. Your brain just has too much going on to process things accurately.

Your body is trying to protect itself. Vomiting is a way for our bodies to rid ourselves of harmful foods and poisons. When your body senses it is in danger, the ANS response may be triggered. The nervous system is acting on high alert to keep you alive. By doing so, it uses those overactive nerves and hormones to get the message to your brain that you are not okay.

If your chronic pain or the medications you take cause consistent nausea, there are several things you can do to help control it. These remedies range from prescription and over-the-counter medication to teas and certain flavors of candy.

Medications to help control nausea are called antiemetics. These kinds of medication serve two purposes: to prevent you from throwing up and to prevent the feeling of nausea. If your nausea affects your quality of life, talk to your doctor about whether a prescription antiemetic may be appropriate.

You can also find a number of antiemetic medications over-the-counter. In addition, antacids and certain antihistamines also can help control nausea. You can always ask your pharmacist for advice as well. However, be sure to keep a record of what you take and share it with your doctor.