An NHS doctor has issued an urgent warning about tap water as he explained a particular practice could expose you to a “brain-eating amoeba”. While water in the UK is safe to drink, it might not be safe for nasal rinsing.

A nasal rinse is a common practice for managing symptoms of colds, allergies, sinus infections, and post-nasal surgery. Water or a saline (a mix of water and salt) is flushed into the nose to wash away mucus, dust, pollen, and other irritants that build up in the nasal passages.

In a video uploaded to social media platform TikTok, Doctor Suraj Kukadia explained the risks of using tap water for this method. The expert, who is better known online as Dr Sooj, said: “Tap water is unsafe for this but it is safe to drink.

“This is because, in tap water, there are bacteria. There are amoeba, there are protozoa. There are things in the water.”

If you are performing a nasal rinse he recommended using water that has been treated in some way. He continued: “Now if you do a nasal sinus rinse please use distilled water, sterile water, sterile saline, or cooled boiled water.

“That’s because the boiling process will destroy a brain-eating amoeba called naegleria fowleri.” Naegleria fowleri is an organism that thrives in warm freshwater lakes, rivers, and hot springs.

It is also known as the “brain-eating amoeba” because it can infect the brain and destroy brain tissue. In the majority of cases, a brain infection from naegleria fowleria proves fatal.

Dr Sooj said: “Our mucus is designed to catch pathogens and we then blow our nose. Our nose runs, we get rid of them, or we swallow that mucus and it gets destroyed in our stomach acid.

“But if you are literally using the water to get rid of all of that mucus it just increases the risk that you might be affected by this amoeba.” However, he noted that it is very rare you would encounter this infection – but it is not “worth the risk”.

“I will say that it is incredibly rare for something like this to happen,” he added. “The reason that it’s safe to drink is because it gets destroyed by your stomach acid.

“And for something as simple as this just it’s not really worth the risk. Just used cooled boiled water, distilled water, sterile water, or sterile saline. Sterile saline will be safe and it’s probably a bit more comfortable because it’s got the salt in it. Any concerns, please go and see a doctor.”

His advice is echoed by the Centres for Disease Control and Prevention (CDC), which warns that rinsing with tap water can not only expose you to naegleria fowleri but acanthamoeba as well.

It says: “Germs such as the amebas naegleria fowleri and acanthamoeba can grow in public and private water tanks and pipes. They can also grow in the pipes and water heaters in some homes and buildings.

“Naegleria fowleri and acanthamoeba can pose a serious risk to your health if they are in the water you use to rinse your sinuses or nasal passages. If the amoebas go up the nose and to the brain, they can cause nearly always fatal brain infections.

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“Although rare, people have died from rinsing their sinuses with tap water containing naegleria fowleri and acanthamoeba.” It advices seeking immediate medical attention if you or someone you know develops a headache, fever, confusion, or vomiting after rinsing your sinuses or nasal passages.

Primary amebic meningoencephalitis

If water containing the amoeba goes up the nose and to the brain, it can cause an infection called primary amebic meningoencephalitis (PAM). “Typically, fewer than 10 people a year in the United States get PAM. Nearly everyone who gets PAM dies from it,” the CDC says.

Early symptoms of PAM can include headache, fever, nausea, and vomiting. PAM progresses extremely quickly. Most people with PAM die within one to 18 days after symptoms begin. The CDC says: “It usually leads to coma and death after 5 days.”

Symptoms can include stiff neck, confusion, lack of attention to people and surroundings, loss of balance, and hallucinations.