Aphthous Ulcers: These are the most common cause of mouth sores and can cause significant tongue irritation. They are benign and recurrent, often triggered by stress, trauma, or certain foods.

Oral Lichen Planus: An autoimmune condition that can cause white patches, redness, and irritation in the mouth, including the tongue.
Oral Candidiasis (Thrush): A fungal infection that can cause white patches and irritation, especially in immunocompromised individuals or those with poor oral hygiene.
Nutritional Deficiencies: Deficiencies in vitamins like B12, iron, or folate can cause mouth sores and tongue irritation.
Irritation from Dentures or Orthodontic Appliances: Poorly fitting dental appliances can cause friction and irritation leading to mouth sores and tongue discomfort.

Oral Cancer: Although less common, mouth sores and tongue irritation can be symptoms of oral cancer. It's crucial to rule out this diagnosis, especially in smokers or those with a history of tobacco use.
Autoimmune Disorders: Conditions like pemphigus or pemphigoid can cause blistering and sores in the mouth and are important not to miss due to their potential for serious complications.
Infectious Diseases: Certain infectious diseases, such as herpes simplex virus (HSV) or syphilis, can present with oral lesions and must be considered to ensure appropriate treatment and prevention of transmission.

Erythema Multiforme: A rare skin condition that can also affect the mucous membranes, causing sores and irritation in the mouth.
Patterson-Brown-Kelly Syndrome (Plummer-Vinson Syndrome): A rare condition characterized by esophageal webs and iron deficiency anemia, which can also cause mouth sores and tongue irritation.
Graft-Versus-Host Disease (GVHD): In individuals who have undergone bone marrow or stem cell transplants, GVHD can cause a range of symptoms including oral lesions and irritation.