A method and apparatus (21, 150) is disclosed for identifying tissue which is suspected of being physiologically changed as a result of pre-cancerous or cancerous activity. The apparatus (21, 150) includes a probe (1, 10; 151) configured to contact the tissue and which includes an arrangement (3-7, 17-47; 158-163) to subject the tissue to a plurality of different stimuli such as electrical, light, heat, sound, magnetic and to detect plural physical responses to the stimuli. The probe (1, 10; 151) connects to an analogue section (23; 152) which buffers signals between the probe (1, 10; 151) and a processor (22; 153). The processor (22; 153) processes the responses in combination in order to categorise the tissue, and then compares the categorisation with a catalogue of expected tissue to identify the tissue, the processing occurring in real-time with an indication of the tissue type (eg. normal, pre-cancerous/cancerous, or unknown) being provided to an operator of the apparatus.