When Body Odor Is an Indicator of Disease, Cancer

When it comes to body odors, many people will first think of the smell of sweat. If a person’s sweat has an unpleasant odor, it may be related to his or her diet. Some people prefer to eat spices such as green onions and garlic, or strong-smelling plants like cilantro. This habit may cause the sweat glands to secrete a special smell of sweat.

However, in general, when the body starts to have a distinct smell, the common causes include blocked sweat glands and/or large sudoriferous glands and local infections.

Some specific body odors are also sometimes associated with chronic metabolic diseases, congenital metabolic abnormalities, and even some cancers.

This is why some animals are trained to diagnose cancer and are called “animal doctors.” Some dogs and cats are trained to detect the smells of cancer patients, and when they encounter a cancer patient, they can quickly identify whether his/her smell is similar to the smells they have learned, and thus identify the patient. Therefore, people use the animals’ sensitivity to smell to help doctors make early diagnosis.

Perhaps in the future, there will be more technological aids to identify differences or changes in human body odors.

Specifically, it is important to be aware of the following body odors when they emerge.

Ammonia or Urine Odor

If you find your sweat smelling like urine or ammonia, you should be careful about the functions of your liver and kidneys.

Changes in body odor are more common in people with metabolic diseases of the liver and kidneys.

According to Dr. Pengchi Liu, chief physician of the Department of Family Medicine at Shin Kong Hospital, these patients have an abnormal metabolism of urea or ammonia, which can cause the sweat glands to secrete such a smell.

What is ammonia? It is a substance produced by your body’s cells and intestinal bacteria, as the body digests and processes proteins. The body treats ammonia as a waste and eliminates it through the liver.

Ammonia can also form urea, which enters the kidneys and is later excreted in the urine.

If urea is not excreted, ammonia will accumulate in the body. This is sometimes a problem for people with poor or even failing liver or kidney functions. The ammonia that is not metabolized is excreted through the breath and sweat.

Patients with uremia will have a distinct odor in their breath, which is called uremic fetor. Some studies found that chronic kidney disease patients have ten times less ammonia in their breath after hemodialysis.

Sour and Rancid Smell in the Mouth

A sour and rancid odor in the mouth and/or nose is usually caused by periodontal diseases or sinusitis. This condition is often associated with bacterial infections, such as staphylococcus or streptococcus.

A paper in the Iranian Journal of Otorhinolaryngology suggests that in 80 percent to 90 percent of the cases, foul breath is due to oral health problems, such as periodontal diseases, while the remaining 10 percent are due to medical conditions in other parts of the body, such as sinusitis.

The bad odor in the mouth mainly comes from the decomposition of proteins in the mouth by bacteria, which in turn produces volatile sulfur compounds. The culprit is mostly chronic periodontal diseases. Periodontal tissues are the main site of volatile sulfur compound production, because its vicinity is full of bacteria, food residues and other wastes.

When sinus inflammation occurs, there will be swelling, and mucus will build up in the nasal cavity, which also causes bacteria to roam in places that are difficult to clean. Their by-products go out through exhalation, which will also cause persistent bad breath.

Dr. Liu added that there are some patients with nasopharyngeal infections, especially with certain specific colonies, and these patients may also smell some fishy or pus-like odor.

Sour and Acidic Odor

Some patients with breast cancer complain of a sour smell like that of dried radish from their body.  Lung cancer and stomach cancer patients also have the problem of sour odors.

The bad odor caused by cancer usually originates from three conditions: necrosis, bacterial infections, and secretions. For instance, if a tumor site has an ulcer, it may cause bacteria to breed and produce a bad odor.

Dr. Liu said that he once saw a patient, who felt a bloody and sour odor in his nose or mouth. At first, the patient thought it was due to sinusitis or allergic rhinitis that caused his abnormal sense of smell, so he had it treated as sinusitis. However, the smell persisted even after he took antihistamines and antibiotics.

Later, he developed gastroesophageal reflux, excessive acidity, and other symptoms of stomach problems. He thought that it was the antibiotics that had hurt his stomach, and continued his treatment. In the end, he found that his stomach problems did not subside and he could still smell the sour and bloody odor near his nasopharynx, and even people around him started to tell him that his breath seemed to have a sour taste.

He finally did a gastroscopy and found out that he had stomach cancer.

Fruity Odor

A fruity body odor may be caused by type 1 diabetes or type 2 diabetes-related ketoacidosis.

The body of a diabetic cannot produce enough insulin, or has insulin resistance, making it difficult to use glucose for energy production. In order to obtain energy, the body burns fat, which in turn produces ketones in the blood.

A high ketone level will cause the blood to become acidic and give the body a fruity odor.

However, this fruity body odor may also be due to reasons unrelated to diabetes, such as a ketogenic diet, fasting, and heavy alcohol consumption.

Fermented Beer Smell

This type of body odor is related to the metabolism of the individual.

Some people with gout have a high uric acid level that makes their sweat and urine smell like fermented beer, or even a little more acidic.

Grape Juice Smell

Some patients with severe pulmonary Pseudomonas aeruginosa infections will have a body odor like grape juice.

Some bacteria have their own distinctive odors, while Pseudomonas aeruginosa produces a sweet grape-like odor. Pseudomonas aeruginosa usually affects the lungs and urinary tract, or causes wound infections.

Bromhidrosis

This foul-smelling body odor may be due to an infection in the large sudoriferous glands.

Sweat glands are located almost all over the body, and their main functions are to excrete sweat and regulate body temperature. One type of sweat glands is called the large sudoriferous glands, which are located only in the armpits and perineum. If the large sudoriferous glands in the armpits are quite strong, and the sweat is not cleaned in time, then bacteria will breed and cause bromhidrosis.

When there is chronic inflammation caused by the blockage of the large sudoriferous glands and repeated infections, it is hidradenitis suppurativa, which we should be alert about. This disease can cause abscesses in the armpits and bring a serious odor.

Behind a Strong Perfume, There May Be a Hidden Disease

Sometimes doctors encounter patients with strong perfumes. These people may have a relatively strong body odor and use a lot of perfume in social settings, which can also cause a dulling of their sense of smell. Therefore, they may not be aware of the changes in their body odor and often have to be reminded by their friends and relatives.

It is recommended that these people pay attention to their body odor after showering, to see if it is unusual.

When Smell Is in the Brain

If a patient goes to the doctor because he or she feels that his or her own body odor is abnormal, the doctor will usually smell the odor first to determine if the smell is the same as the patient describes, and if there is a problem.

Some patients who consider their own body odors strange end up finding out in the hospital that the problem is with the olfactory nerves in their nasal cavity. Then there’s the possibility that they may have a brain disease.

The matter of smell itself is subjective. Most people’s body odors are not a warning sign of any disease. However, if there is an unacceptable body odor, or if there is a strange sour or foul odor, then the individual may want to look into it and see if there is a more serious problem.

Epoch Health articles are for informational purposes and are not a substitute for individualized medical advice. Please consult a trusted professional for personal medical advice, diagnoses, and treatment.