Yes. A mild TBI or concussion can still form the basis of a valid brain injury lawsuit if it was caused by someone else’s negligence and resulted in measurable harm. Many people assume that only severe TBI cases qualify for legal action. That is not accurate. If a mild TBI leads to ongoing symptoms such as difficulty concentrating, mood swings, missed work, or medical expenses, you may pursue compensation. The strength of the case depends on medical documentation, proof of fault, and evidence of how the injury affected your daily life.