Nausea and vomiting

Definition

Nausea is feeling sick
Vomiting is being sick.

Epidemiology

Very, very common. Almost every drug lists this as a side effect. Almost every condition can cause it. I feel a bit sick myself right now, actually. Bleuururaaagh!

Pathophysiology

Five types:

1. Sensors in the GI tract and in the blood chemoreceptor bit in the brain sense a toxin, and make the brain centre go "Meh!"
2. The inner ear's vestibular apparatus can get messed up, causing vertigo and nausea.
3. Higher functions in the brain can stimulate nausea, such as memory of a horrible smell.
4. Drug side effects, such as chemotherapy or morphine.
5. A tumour or stroke affecting the vomiting centre.

Clinical and Associated Features

Medical Emergency - If you get nausea and vomiting with any of these, you need to be more worried, and go immediately to A&E:

• blood in the vomit (haematemesis)
• severe headache or stiff neck
• confusion
• decreased consciousness
• severe abdominal pain

Differential Diagnosis

There are so many causes, it's pointless to try and learn them all.

Most causes of nausea are GI, such as food poisoning, pancreatitis, intestinal obstruction, gastroenteritis, gastritis. Aside from these, learn the ABC's of Non- GI causes of vomiting:

• Acute renal failure
• Brain (Increased ICP)
• Cardiac (Inferior MI)
• DKA
• Ears (labyrinthitis)
• Foreign substances (Alcohol Tylenol, theo, etc)
• Gravidarum
• Hypercalcalcaemia, Hyponatraemia.
• Infections (pyelonephritis, meningitis)