Diagnosis of trigger points typically takes into account symptoms, pain patterns, and manual palpation. When palpating the therapist will feel for a taut band of muscle with a hard nodule within it. Often a local twitch response will be elicited by running a finger perpendicular to the muscle fibres direction. Pressure applied to the trigger point will often reproduce the pain complaint of the patient and the referral pattern of the trigger point. Often there is a heat differential in the local area of the trigger point.