Whether it creeps up slowly or hits suddenly, nausea—and its unwelcome partner, vomiting—can be incredibly unpleasant. Almost everyone has experienced it at some point, but what exactly causes it? And when should you be concerned?
Let’s dive in.
What is Nausea and Vomiting?
In simple terms, nausea is that queasy, unsettled feeling in your stomach that often comes before vomiting, the forceful emptying of stomach contents through the mouth.
These aren’t diseases themselves, but symptoms—signals from your body that something’s not quite right. Nausea is extremely common and can be triggered by anything from motion sickness to anxiety to serious illnesses.
💡 Did you know?
According to the World Health Organization, nausea and vomiting are among the top 10 most reported symptoms in hospital visits worldwide.
How Does It Happen?
Your body treats vomiting like a built-in safety alarm. Think of your brain as the control tower. There’s a part of it—called the vomiting centre—that takes in signals from all over the body. These include:
- Your inner ear (balance and motion)
- Your digestive tract (toxins, infections)
- Your bloodstream (medications, chemicals)
- Even your emotions (like fear or anxiety)
Once the vomiting centre receives a strong enough signal, it responds with a coordinated effort: your diaphragm contracts, your abdominal muscles tense up, and your stomach contents are expelled—whether you like it or not.
Nausea, meanwhile, is the brain’s way of warning you before this dramatic reaction kicks in.
What Causes Nausea and Vomiting?
It’s a long list, but here are the most common causes:
- Infections (30-40%): Stomach bugs caused by viruses or bacteria—like norovirus or food poisoning—are a leading cause.
- Motion sickness (10-15%): The disconnect between your visual and inner ear signals can make travel miserable.
- Pregnancy (10%): Especially in the first trimester. This is called morning sickness, though it can strike any time of day.
- Medications or chemotherapy (10%): Some drugs irritate the stomach or affect the brain’s nausea centres.
- Gastrointestinal issues (5-10%): Conditions like gastritis, ulcers, or reflux can trigger nausea.
- Psychological triggers (variable): Anxiety, stress, or even certain smells can be enough.
Less common but more serious causes include head injuries, migraines, kidney failure, liver disease, or blocked intestines.
Who’s at Risk?
While nausea and vomiting can affect anyone, certain groups are more prone to it. For example:
- Children often vomit more easily than adults, especially when sick.
- Pregnant women, especially in early pregnancy.
- Cancer patients receiving chemotherapy.
- People prone to migraines or vertigo.
- Those with a sensitive stomach or high stress levels.
Risk increases when you’re dehydrated, skipping meals, or in high-motion environments like boats or amusement park rides.
Other Symptoms That May Come Along
Nausea rarely comes alone. You might notice:
- Loss of appetite
- Sweating or pale skin
- Dizziness or light-headedness
- Excessive salivation
- Abdominal discomfort
If vomiting becomes severe, you may also see signs of dehydration—dry mouth, dark urine, fatigue—or electrolyte imbalances, which can cause muscle cramps and confusion.
Red flags that suggest a serious issue include:
- Vomiting blood
- Greenish (bile) or fecal-smelling vomit
- Severe headache or stiff neck
- High fever
- Inability to keep fluids down for more than 24 hours
Tests to Identify the Cause
Doctors don’t always need fancy tools to figure out what’s causing nausea—they often rely on history and physical exam. But when deeper issues are suspected, tests may include:
- Blood tests (to check for infection, kidney/liver function, electrolyte imbalance)
- Urine tests
- Ultrasound (often in pregnancy)
- CT scan or MRI (for head injuries or abdominal blockages)
- Endoscopy (if stomach lining issues are suspected)
If dehydration is a concern, doctors might also test blood urea and creatinine levels to check how well your kidneys are functioning.
How Is Nausea and Vomiting Treated?
The first step? Find and treat the cause.
For mild cases (like food poisoning or motion sickness), rest and fluids are usually enough. But if vomiting is persistent, treatment options include:
💊 Medications (Gold Standard)
- Ondansetron (Zofran) – blocks nausea signals in the brain.
- Metoclopramide (Maxolon) – helps move food through the stomach faster.
- Domperidone – similar to metoclopramide, with fewer central nervous side effects.
- Promethazine – useful for motion sickness or pregnancy-related nausea.
Always consult a doctor, especially for children or pregnant women.
🥤 Home Remedies
- Sip clear fluids (e.g., water, oral rehydration salts, flat ginger ale).
- Try ginger, peppermint, or lemon—these can soothe the stomach.
- Eat bland foods like crackers, rice, or toast once you’re able.
🛑 What to Avoid:
- Fatty, spicy, or overly sweet foods.
- Large meals—small, frequent ones are better.
- Strong smells or heat, which can make nausea worse.
In severe cases—especially when vomiting leads to dehydration—you may need IV fluids and even hospitalisation.
When Should You See a Doctor?
Reach out for medical help if:
- Vomiting lasts more than 24 hours (12 for kids).
- You can’t keep fluids down.
- You’re vomiting blood or something that looks like coffee grounds.
- You’re experiencing severe pain, confusion, or signs of dehydration.
Final Thoughts
Nausea and vomiting are common, but they shouldn’t be ignored—especially when they’re intense or persistent. While most cases are minor and resolve on their own, some point to deeper issues that need medical care.
So the next time your stomach starts acting up, ask yourself: Is it something I ate? Something I’m anxious about? Or something more?
Your body might just be trying to tell you something important.
References
- Nausea and Vomiting, Merck Manual, 2024. https://www.merckmanuals.com/home/digestive-disorders/symptoms-of-digestive-disorders/nausea-and-vomiting
- Nausea & Vomiting Overview, Cleveland Clinic, April 2023. https://my.clevelandclinic.org/health/symptoms/17881-nausea-and-vomiting
- Nausea and Vomiting Causes, Mayo Clinic, February 2024. https://www.mayoclinic.org/symptoms/nausea/basics/causes/sym-20050736