The taste sensation is one of the many ways that we experience our environment. It is useful for assessing foods and fluids and can bring tremendous pleasure in what we eat and drink. It also plays an important role in compelling us to eat or avoid certain substances that can either nourish us or harm us. We always associate taste with whatever we put in our mouths. But sometimes there can be tastes elicited even though we have not eaten or drunk anything.
If your taste sensation is disrupted, the medical term is dysgeusia. When we experience a bad taste in the mouth it is known as cacogeusia. A funny taste in the mouth goes beyond abnormal taste sensations when tasting something. These strange tastes may however be emanating from the body itself. Apart from saliva which we feel but do not taste, there a host of other substances and secretions from the body that can stimulate the taste sensation. It can even be due to different disorders affecting the taste centers in the brain even without putting any substance in the mouth.
Stomach Acid in the Mouth
Acid reflux is a common problem. It is more correctly known as gastroesophageal reflux disease (GERD) where the acidic contents of the stomach pass up into the esophagus. Typically it causes heartburn and nausea but some people have no symptoms. The acid can reach up as high as the throat, mouth and even the nose. The acid not only damages the tissue lining the esophagus, throat and mouth. It can also be tastes and has a characteristic sour taste.
Most of the time you would be able to identify a sour taste in the mouth as being due to stomach acid when it is accompanied by heartburn, nausea and indigestion. However, people who suffer with silent acid reflux may only have symptoms like a sour taste or sore throat typically in the morning after awaking from sleep. Sometimes the taste may be more bitter than sour. This is usually with bile reflux, where bile from the gallbladder travels from the duodenum (small intestine) all the way up to the mouth.
Poor Oral Hygiene
Brushing your teeth daily, twice daily preferably, with flossing and rinsing using a good mouth wash are the key practices in maintaining good oral hygiene. The mouth is teeming with bacteria that feeds off the food particles between the teeth, on the tongue and the other nooks and crannies within the mouth. A range of mouth and dental problems can arise with poor hygiene which may cause a funny taste in the mouth. However, even if these problems are not present, poor oral hygiene may on its own contribute to a strange taste in the mouth.
It is not just about a furry tongue and teeth when you do not brush regularly. Food that is not removed from the mouth through good dental practices eventually decomposes in the mouth. It is further added to by the action of bacteria which may also release their own byproducts. We all know that the mouth odor may be offensive. But we do not often consider that the strange, sometimes even putrid, taste in the mouth is a result of the decomposing food and bacteria.
Mouth and Dental Problems
A number of different mouth and dental problems can arise and a strange taste in the mouth may be one of the symptoms. From tooth decay to gingivitis and oral candidiasis, any disease involving the mouth and teeth may affect the taste buds. Sometimes it is due to secretions from the diseased area but at other times it may be that the disease process is causing an abnormal stimulation of the taste buds. Many of these conditions are related to poor oral hygiene which on its own can cause a funny taste in the mouth.
It is important to see a dentist regularly so that any orodental problems can be identified. Should a strange taste arise suddenly, then a dental consultation is necessary. Sometimes there may be no other symptoms apart from the unusual taste sensations. Most people ignore the taste until the condition has progressed and even when complications arise. With oral or dental problems, the strange taste in the mouth can vary significantly from a metallic taste to a rotting or bitter taste in the mouth.
Ear, Nose and Throat Problems
The mouth is connected to the nose and even the ear through the throat. The nasal passages continues into the throat (nasopharynx) which meets with the mouth and throat passage (oropharynx). A long channel known as the eustachian tube running from the middle ear also connects to the back of the throat. Therefore problems that occur in the nose and paranasal sinuses, middle ear or throat and tonsils can cause symptoms in the mouth. It is mainly associated with secretions, pus, blood and decomposing tissue.
When these secretions or blood from these areas enter the mouth, it may make contact with the taste buds and cause a strange taste – sometimes bitter or even offensive taste in the mouth. The sense of smell (nose) also impacts taste so when the olfactory (smell) receptors are affected, the taste sensation may also be affected. In addition, the nerves that carry taste impulses back to the brain may also be affected when there is a middle ear infection (otitis media). This can cause abnormal taste sensations (dysgeusia).
Taste Sensation Disorders
The taste buds are receptors mainly located on the tongue. Different taste buds are stimulated by different chemicals from food that dissolve in saliva. Impulses emanating from the taste buds travel through three cranial nerves to the brain stem which in turn sends signals to different parts of the brain. These areas are collectively known as the taste centers, where taste is perceived and associated with memories and other cognitive abilities. This is how we experience the sense of taste.
However, a host of problems can arise which affects the normal taste sensation or may cause us to perceive tastes that do not exist. The problem may lie in the taste buds itself, the nerves that carry taste signals or parts of the brain decoding these signals. This can arise with nerve disorders, pressure on the nerves or brain, tumors and other types of diseases affecting the mouth, nerves and brain. A strange taste in the mouth even when there is no food or drink being ingested can therefore be a symptom of these problems.
Blood Glucose Disorders
Alterations in blood glucose levels can cause a strange taste in the mouth. In diabetes, where the blood glucose levels may rise higher than normal at times, some diabetics report a range of unusual tastes in the mouth ranging from a sweet or fruity to metallic and even a bitter taste. These strange taste sensations may also occur with a drop in blood glucose levels. Although it is not a widely known symptom, abnormal taste sensations may be present both in hyperglycemia (high blood glucose) or hypoglycemia (low blood glucose).
Diabetics are at the risk of complication known as ketoacidosis where the body breaks down fat and there is massive accumulation of a byproduct known as ketone bodies in the blood stream. It can be very dangerous. Normal fat breakdown also results in ketone body formation (ketosis) but it is usually moderate and can be removed from the body. In these conditions. a person may perceive a strange taste in the mouth. Apart from diabetes, people who have not eaten for long periods and where the body has to resort to deriving energy from the fat stores will also experience a funny taste in the mouth.
Medication and Other Substances
A number of different substances can alter the taste sensation, elicit abnormal tastes or coat the tongue leading to a sustained taste in the mouth. Various medication may have this effect, especially if it is chewed, placed under the tongue for sublingual absorption or not swallowed quickly with water. Some medication can also have an effect on the taste centers in the brain or even irritate the nerves that carry taste signals. Chronic medication may also affect the taste sensation in other ways like causing dryness of the mouth and increasing the risk of dental problems.
Alcohol, tobacco and even illicit drugs may also cause strange tastes in the mouth. Alcohol and illicit drugs can disturb the functioning of the taste buds, nerves and taste centers in the brain. Illicit drugs may cause hallucinations which may also involve the taste sensation. Some alcoholic drinks may adhere to the surface of the mouth and the breakdown products of alcohol may also stimulate the taste buds. Tobacco chewing or smoking tends to dull the taste sensation but tobacco residue can adhere to the tongue and inner lining of the mouth. This can cause abnormal tastes in the mouth.
Article reviewed by Dr. Greg. Last updated on March 22, 2013