I have a disc herniation so how can they fix it?

They usually don't: Disk herniation is actually more common than people realize because it doesn't always cause symptoms. If it is causing compression, and the pain is getting worse or is unbearable, you can undergo surgery. Most people's issues resolve without surgery and usually one year out the people who have had surgery fare no better. Surgery should be a last resort.

90% are treated : without surgery with time the biggest healer along with guided exercise, activity modification, not smoking, and for symptom relief-use of various medications if no contraindications like oral steroids, NSAIDs, Neurontin or Lyrica (pregabalin). Epidural steroid injections can be considered. If no better &leg or arm symptoms predominant over back or neck pain, surgery an option with > 90% success rate.