Hi they did a ct scan and told me that incidentally they saw a hemangioma on my lower thoracic spine, can i still exercise and is it dangerous. help?

Hemangiomas: are common incidental findings when imaging the spine. They are benign, and generally of no concern. Some radiologists don't bother mentioning them in their reports. They are only a potential problem if they are very large(causing the vertebral body to be weaker and more prone to fracture) or expansile. But that is very unusual, and highly unlikely if yours was only mentioned as "incidental"