This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
The headaches of fever, and the headaches which are present in connection with various other diseases, as gout, neuralgia, rheumatism, diseases of the heart, kidneys, and organic affections of the brain and spinal cord, are cured only by the relief of the primary diseases of which the headache is symptomatic. When these are curable, the headache will disappear as improvement in the disease takes place. When incurable, as in organic disease, the pain in the head will, of course, be obstinately persistent.