Inflammation or damage to the lateral femoral cutaneous nerve, which may cause pain or numbness on the outer thigh.
To support a rating at any level, medical records and examination findings should document how much function the nerve has lost. For a severe to complete picture, evidence would need to show something beyond purely sensory loss, because the regulation caps wholly sensory involvement at the mild or moderate degree. For mild or moderate involvement, records showing sensory symptoms such as numbness, tingling, or pain along the outer thigh, with limited or no objective loss of nerve function on examination, would reflect that level.
Nerve conduction studies or electromyography results that measure how well the nerve is working can be relevant, as can a VA or private examination that describes the degree of sensory change or any motor findings. Your own statements, and statements from people who know you, describing how thigh symptoms affect your ability to stand, walk, or carry out daily tasks can help show the functional impact. If both thighs are affected, evidence documenting each side separately helps VA apply the correct combined rating.
Conditions that are often caused or made worse by this one. If you have any of these, they may be claimable as secondary service connection.