Low-grade glioma

A glioma that grows slowly. Usually grade 1 or grade 2.

What a low-grade glioma is

A low-grade glioma grows slowly. Doctors grade brain tumors from 1 to 4. Low grade means grade 1 or grade 2.

Slow does not mean harmless. Where a tumor sits can matter as much as how fast it grows, because it presses on the part of the brain around it.

What often happens

Because these grow slowly, a care team may watch a small one with scans for a while before doing anything. That plan has a name: active surveillance. Being watched is a real plan, not a delay.

Some low-grade gliomas change over time and start growing faster. That is why your team keeps checking.

What to ask your team

This is not medical advice. It explains research in plain words. Your care team knows your case. Talk with them before you make any decision about your treatment.

Last reviewed: August 16, 2026

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