Working on figuring out cause of my constant lightheadedness but wondering if it is dangerous to brain to have constant lightheaded feeling for days?

Many reasons: A feeling of dizziness or being light in the head is very common and can have multiple causes. A common cause is medication and dietary changes. Does anything make your symptoms better or worse? Consider seeing a doctor to discuss this symptom.

Not dangerous: The lightheadedness in itself is not directly damaging to the brain. However constant lightheadedness can be a symptom of something serious such as low blood. Most commonly, lightheadedness can simply be a sign of dehydration, inner ear problems, sinusitis, or medication interactions. Lightheadedness alone, without any other associated symptoms is likely benign.