Tooth decay
What your mouth can tell you about your health
The mouth is a busy place, engaged in eating, drinking, breathing, smiling, frowning and talking all hours of the day. It is vulnerable to constant attack from microbes, as well as the wear and tear from nearly constant activity. As a portal into the body’s respiratory and digestive tracts, the mouth is also a window into your overall health. Here are some of the many conditions that can affect the human mouth.
Gum disease
Gum disease![]()
Gum disease begins with gingivitis, inflammation of the gums characterized by swollen, red gums that bleed easily. The inflammation is caused by the accumulation of bacteria (in the form of plaque) at the base of the teeth. If left untreated, the disease can progress to periodontitis, a severe gum infection that can destroy gum tissue and the bone that supports teeth.
Temporomandibular joint disorder
Temporomandibular joint disorder
Temporomandibular joint disorder, or TMD, is a painful condition involving the jaw joint that connects the lower jawbone with the skull, a complex, hardworking joint involved in chewing, swallowing, speaking and yawning. Symptoms of TMD can include jaw pain, difficulty opening or closing the mouth, and a clicking or popping noise during jaw movement.
Bruxism
Bruxism ![]()
Bruxism is clenching or grinding teeth when not eating. Because it usually takes place during sleep, it is considered a sleep-related movement disorder, though it can also happen while awake. It’s most common in children, and can be associated with stress and sleep apnea in adulthood. Signs you may clench or grind your teeth include poor sleep, headaches, neck and jaw pain, worn or damaged teeth, and scalloped indentations in your tongue.
Odontomas
Odontomas 
Odontomas are benign tumours composed of dental tissue that can appear as an extra tooth or collection of small teeth. It’s the most common type of dental tumour, usually diagnosed in adolescence or early adulthood. Symptoms are often absent but can include pain, swelling and delayed eruption of permanent teeth. In a notable case in Chennai, India, a tumour in a seven-year-old boy’s lower jaw was found to contain 526 extra teeth.
Orofacial clefts
Some babies are born with a split in the roof of the mouth and/or lip, known as cleft palate and cleft lip. Clefts can occur in either lip, palate, or both; and on one side of the mouth or both. This condition occurs very early in the pregnancy when the tissues or bony structures of the embryo’s lip and mouth don’t fuse together properly, a result of genetic and environmental factors such as folic acid deficiency, smoking, diabetes, obesity, viral infections, and the use of certain medications during pregnancy.
Bad breath
Bad breath
Bad breath was catapulted into the spotlight by a 1920s Listerine marketing campaign that promoted an antiseptic rinse—then used for scrubbing floors and treating gonorrhea—as a cure for “chronic halitosis” (and incidentally triggering generations of social anxieties about bad breath). Halitosis is typically caused by tonsil stones, tooth decay, gum disease and oral or sinus infections, but it can also point to more serious conditions like diabetes, lung cancer and cystic fibrosis.
Dry mouth
Dry mouth![]()
Dry mouth—formally, xerostomia—is a common condition that is not a disorder in itself but rather a symptom or side effect. It can be caused by medications that reduce salivary flow, mouth-breathing due to nasal congestion, dehydration, damage to salivary glands such as from cancer radiation therapy, and autoimmune conditions like Sjögren’s syndrome that attack salivary cells. Dry mouth affects both quality of life and oral health, causing discomfort, affecting the ability to taste, making speaking and swallowing difficult, and increasing vulnerability to dental caries and fungal infections.
Burning mouth syndrome
Burning mouth syndrome
Burning mouth syndrome is a painful condition defined by a recurring or ongoing scalding sensation in the tongue, lips or mouth. It’s often accompanied by dry mouth and taste changes, and is most prevalent in post-menopausal women. The syndrome’s cause is poorly understood but may be linked to nerve damage caused by hormonal changes.
Oral hypersensitivity reactions
Oral hypersensitivity reactions![]()
Oral hypersensitivity reactions are abnormal reactions in and around the mouth to even small amounts of usually harmless substances, including foods, medications, dental amalgams and anaesthetics. Symptoms can include life-threatening allergic reactions like anaphylaxis, or milder symptoms such as swelling, itching, burning or ulcers in the mouth, as well as a type of gingivitis that turns the gums bright red. The reaction can be immediate or delayed, which may hinder identification of the substance at fault.
Laryngitis
Laryngitis
Laryngitis is the temporary or chronic inflammation of the larynx (also known as the voice box or glottis), an organ in the throat that contains the vocal cords and protects our airways from food debris, causing hoarseness, sore throat and/or cough. The most common cause of laryngitis is respiratory infection such as a cold or flu; non-infectious causes include vocal strain, acid reflux, allergies, cancer, autoimmune disease, polyps, and exposure to smoke and other inhaled irritants.
Tonsillitis
Tonsillitis![]()
Tonsillitis is an infection of the tonsils marked by inflammation, sore throat, enlarged neck glands and fever. Tonsils are tiny organs that form part of the lymph system; the palatine tonsils are the most commonly known, and sit at the back of the throat on each side. Tonsillitis occurs most frequently in children, and some people will have their tonsils removed if they suffer from chronic tonsillitis.
Mouth ulcers
Mouth ulcers
Mouth ulcers are small, shallow lesions found on the tongue, inner cheeks, inner lips or roof of the mouth. Aphthous ulcers—also known as canker sores—are the most common type and usually resolve on their own, but mouth ulcers can also be linked to a wide variety of conditions including viral infections such as COVID-19 and chikungunya, gastrointestinal diseases such as celiac and Crohn’s, autoimmune disorders, as well as benign or malignant tumours.
Herpangina
Herpangina ![]()
Herpangina is a common and contagious viral illness that causes small, red-ringed bumps in the back of the throat, and is often accompanied by fever, swollen glands, sore throat and loss of appetite. It’s most common in children up to 10 years old but can occur in all age groups. Herpangina is an enterovirus infection—from viruses that attack the gastrointestinal system-–and is often passed on through contaminated feces.
Herpes simplex virus
Herpes simplex virus
The herpes simplex virus type 1 (HSV-1) is a highly infectious virus that typically invades nerve cells around the mouth and can cause outbreaks of painful, fluid-filled blisters on and around the lips, also called cold sores or fever blisters. Infection is lifelong, and more than two-thirds of adults worldwide will contract the virus by age 50. Carriers can be completely asymptomatic, or experience periodic outbreaks of blisters; outbreaks are often preceded by feelings of tingling, heat, itching or pain where blisters will appear.
Strep throat
Strep throat![]()
Strep throat (pharyngitis) is a contagious, bacterial throat and tonsil infection caused by Streptococcus pyogenes, a bacterium that is also responsible for scarlet fever. Most common in children from five years old, strep throat is characterized by fever, throat pain (especially when swallowing), red and swollen tonsils, and tiny red patches on the roof of the mouth. Younger children may also experience nausea and vomiting. Left untreated, strep throat can cause rheumatic fever and kidney disease.
Thrush
Thrush
Thrush—oral candidiasis—is an overgrowth of Candida albicans, a yeast fungus normally found in our gastrointestinal and skin flora that can sometimes proliferate and cause serious infections. Oral infections tend to be minor in those with healthy immune symptoms, and are characterized by fuzzy white “cottage cheese” patches on the tongue, inner cheeks, roof of the mouth and back of the throat. Thrush is common in babies, whose immune systems are immature, and can be passed back and forth during breastfeeding.
Oral cancer
Oral cancer![]()
Oral cancer is the eighth-most common cancer in men, affecting roughly 200,000 people worldwide each year, particularly older adults. All parts of the mouth can be involved, including lips (where UV ray exposure is often a factor), tongue, palate, cheeks and gums. The most common type is squamous cell carcinoma, linked to tobacco and alcohol use and the human papilloma virus (HPV). Signs to look out for include sores or ulcers that don’t heal, white or red patches, loose teeth, bleeding, difficulty swallowing and weight loss.
Macroglossia
Macroglossia 
Macroglossia is a rare condition defined by an abnormally large tongue that can interfere with eating, breathing, talking, and tooth and jaw development. In cases where the tongue protrudes from the mouth, ulcers can form at the tip of the tongue. The condition can be congenital—as an isolated condition or linked to disorders such as Down syndrome—or acquired. There are a wide range of non-congenital causes, including autoimmune and infectious diseases and metabolic disorders.
Melkersson-Rosenthal syndrome
Melkersson-Rosenthal syndrome![]()
