Viral Upper Respiratory Tract Infection (URTI): This is the most common cause of sore throat and runny nose, often resulting from viruses such as rhinovirus, coronavirus, or adenovirus. The symptoms are typically self-limiting and include cough, sneezing, and sometimes fever.

Allergic Rhinitis: This condition can cause runny nose, sneezing, and sometimes a sore throat due to postnasal drip. It's often seasonal or related to specific allergens.
Influenza: Although more severe, influenza can start with symptoms similar to a common cold, including sore throat and runny nose, but is typically accompanied by higher fever, body aches, and fatigue.
Streptococcal Pharyngitis: A bacterial infection that causes a sore throat, which can be accompanied by a runny nose if there's associated sinusitis or if the infection spreads.

Epiglottitis: A severe and potentially life-threatening condition that can cause a sore throat, difficulty swallowing, and sometimes respiratory distress. It requires immediate medical attention.
Lemierre's Syndrome: A rare but serious condition that starts with a sore throat and can progress to include high fever, neck pain, and swelling, due to a bacterial infection.
Mononucleosis (Mono): Caused by the Epstein-Barr virus, it can lead to a severe sore throat, fever, and lymphadenopathy. Although not immediately life-threatening, it can lead to complications like splenic rupture.

Diphtheria: A bacterial infection that can cause a sore throat and sometimes a runny nose, characterized by a distinctive membrane covering the tonsils and throat.
Tuberculosis (TB): Although rare in many parts of the world, TB can cause chronic symptoms including a sore throat and cough, among other systemic symptoms.
Wegener's Granulomatosis (Granulomatosis with Polyangiitis): A rare autoimmune disorder that can cause a variety of symptoms including sore throat, runny nose, and sinusitis, due to inflammation of the blood vessels.