An occurrence of sinusitis can cause dizziness due to the infection blocking the nasal ducts, thus creating pressure within the inner ear, details WebMD. Adequate water intake helps thin trapped mucus, allowing better flow between the sinuses and inner ear canals.
The eustachian tube bridges the back of the throat to the middle ear, which regulates balance in the body, according to Healthline. Dizziness is felt when that balance is altered by built up pressure or blockage from mucus.
Sudden movements such as standing up too fast or shaking the head can cause sinus-inflicted dizziness, details WebMD. Frequent bending of the head can alter balance as well, creating dizziness.