Do tarlov cyst symptoms always get worse?

No: Tarlov cysts are usually asymptomatic. This means they do not typically cause symptpms/problems. They are often just benign occasional findings on mri's.

Most Tarlov cyst are: Asymptomatic. And just incidental findings. Like taking a picture of someone's face and seeing a birthmark on the photo. The birthmark is not the reason for headaches.... See your spinal specialist, he/she will let you know if yours is the cause of any symptoms. Most do not cause symptoms.