When to worry about lightheadedness and brain tumors? are there any other symptoms along with lightheadedness that represent warning signs?

Unlikely, but talk: Lightheadedness is not a common symptom of a brain tumor. More common are severe headaches, or changes in how your body works due to where a tumor is located. However, you are concerned so should plan to talk with someone. I would explore why you are worried and look for the most likely cause (dehydration, meds, etc).

Yes: Increase in pressure in the skull can present with morning nausea and vomiting. Any change in balance or loss of coordination can also be signs of tumors in the brain. Rarely increase in urination as well.