The brain itself may not have any pain-sensitive nerve receptors, but that doesn’t mean the inner head can’t experience pain… as anyone who’s had a headache will know. The most common form of headache is the tension headache. When the muscles in your body stay semi-contracted for a period of time – for example, when we feel stressed and can’t seem to relax – this is known as muscle tension. Such tension in the meninges (the membranes that help protect the brain), or the face, neck and scalp muscles activate the body’s pain receptors, sending impulses to the brain’s sensory cortex and signalling pain and causing a headache.
More frequent in women than men, the primary tension-type headache manifests itself as a dull ache across both sides of the head. Secondary headaches, meanwhile, can be caused by an underlying health condition such as meningitis, a blow to the head or other sinus-related ailments.