New Delhi, Aug. 6 -- 'The Walking Dead' star Kelley Mack died at the age of 33 after battling a rare disease called Glioma, a condition reportedly diagnosed in 25% brain tumour cases in the United States.

Here's all you need to know about Glioma, its types, causes and more -

A glioma is a tumour that develops when glial cells grow uncontrollably. Glial cells typically support nerves and assist the functioning of your central nervous system, according to the Cleveland Clinic.

Gliomas are malignant or cancerous tumours, although some grow very slowly. They are primary brain tumours, meaning they are formed in the brain tissue. While gliomas rarely spread outside the brain or spine, they can still be life-threatening because they are diff...