Nausea: All You Need to Know, Doctor-Reviewed

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woman with nausea

Nausea can be very unpleasant. While it is a common symptom that may not immediately catch your attention, it can sometimes be a warning sign of something more serious. Here’s all you need to know about it. 


What is nausea? 

Nausea feels as though you are about to throw up. You may feel discomfort in the stomach or the back of the throat. Vomiting may or may not follow. It is very common and happens to everyone, both children and adults, from time to time. 


Nausea is not a disease itself but a prevalent, non-specific symptom of numerous conditions affecting different body parts. It usually lasts for a short period of time and often disappears without the need for treatment. 

What causes nausea?

The most common causes include: 

  • Infections: especially those involving viruses and affecting the stomach or intestines, e.g. gastroenteritis (stomach flu) 
  • Medications: examples include chemotherapy (e.g. doxorubicin), antidepressants (e.g. amitriptyline), antibiotics (e.g. erythromycin), painkillers (e.g. tramadol), contraceptive pills as well as anaesthesia. 
  • Motion sickness: when people are in a moving vehicle or ride, such as car (car sickness), boat (seasickness) and roller-coaster.  
  • Food poisoning: due to bacterial toxins in contaminated or spoiled food 
  • Morning sickness: over 50% of pregnant women experience nausea, particularly from the 6th week to the 12th week of pregnancy
  • Gastrointestinal problems: including gastrointestinal reflux disease (stomach acid going up to the esophagus), small bowel obstruction, gastroparesis and appendicitis.
  • Vertigo: a sensation that you feel everything is spinning due to a problem in the inner ear or part of the brain that controls balance. 
  • Headaches or migraines
  • Excessive alcohol consumption.
  • Low blood sugar.
  • Nausea after surgery.
  • Sign of any underlying medical condition i.e. severe kidney or liver disease.

Nausea can also be triggered by: 

  • Emotional stress or psychological illness: e.g. anxiety and bulimia
  • Problems with the brain or head: e.g. tumor, meningitis, concussion (a mild traumatic brain injury) and bleeding.
  • Certain smells, sights and tastes. 
  • Heart attack: other signs and symptoms apart from nausea are chest discomfort and shortness of breath. 
  • Electrolyte imbalance: too much or too little of electrolytes, for example calcium, sodium, phosphate and potassium, can lead to nausea. 

When to see a doctor

Although nausea is temporary and mild most of the time, it is important to contact your GP if you: 

  • Have symptoms persisting for a few days.
  • Feel nauseous very often.
  • Develop symptoms of a heart attack, e.g. chest pain, pain that spreads to your back, arms, neck or jaw and difficulty breathing.
  • Show symptoms of dehydration, e.g. tiredness, thirst, dry lips, dizziness and dark yellow urine. 
  • Have severe belly pain.
  • Have severe headaches and neck stiffness.
  • Have a high temperature.
  • Vomit at the same time, and the vomiting lasts for more than 24 hours. 

How to treat nausea

Treatment depends on taking a history and examination to assess the underlying cause.


It’s important to do a blood test and scan to assess if there are any underlying medical conditions that first need to be treated.


Antiemetics, i.e. medications that alleviate nausea and vomiting, can be bought over-the-counter in pharmacies, supermarkets or convenience stores in Hong Kong.


Common antiemetics include dimenhydrinate, prochlorperazine, promethazine, metoclopramide, and ondansetron. 


Try to avoid taking drugs during pregnancy. Alternatives such as ginger and vitamin B6 may help. 

If nausea is one of the side effects of the medicines you are taking, inform your doctor or pharmacist when it becomes intolerable. They will help you make the most suitable choice in changing the medicines. 

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Having a nausea? Expert tips to feel better

  • Ensure adequate fluid intake such as water, warm tea, but avoid fizzy drinks as they can cause bloating and worsen nausea. 
  • Try eating bland and soft foods, for example bananas and plain yogurt. 
  • Eat ginger. You can have ginger tea or incorporate ginger into your dishes. 
  • Try sports drinks as they contain plenty of electrolytes that may help in easing nausea. 
  • Avoid foods rich in fats and hot spices. 
  • Take vitamin B6 supplements for nausea during pregnancy. A number of studies have shown its effectiveness. 
  • Eat small meals more frequently. 
  • Avoid strong smells and unpleasant odours. 
  • Get some fresh air by going for a walk or opening a window. 
  • Breathe deeply and slowly. 
  • Find some distraction, for instance watching a movie.
  • Sit straight and do not lay down immediately after eating. 
  • Do not wear clothes that are tight around your belly or waist. 

How to prevent nausea 

There are some medications that you can take beforehand, to avoid general nausea. These include hyoscine


If you know your nausea triggering factors, such as strong smells and car rides, avoid them if possible. Also, try not to read or use your phone in the car or on a ferry as they can make nausea worse! 


Don’t miss our other practical guides to common symptoms, doctor-reviewed:

This article was independently written by Healthy Matters and is not sponsored. It is informative only and not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be relied upon for specific medical advice.

Dr. Wong Shu Ting Lily
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