Noise sensitivity increases the degree of reactivity to noise. It may be a part of a more generic sensitivity to environmental stimuli. Multiple chemical sensitivity (MCS) encompasses a wide range of subjective symptoms provoked by exposure to low levels of chemicals. It has to some extent been accompanied by noise sensitivity indicating a moderate correspondence between them. This narrative review will evaluate the similarities and differences in the characteristics, mechanisms and genetic predisposition of noise sensitivity and MCS. Noise sensitivity is a more common trait than MCS. Most patients with MCS have been women while noise sensitivity has been equally present in men and women. Weinstein’s Noise Sensitivity Scale and QEESI’s Chemical Intolerance Subscale differentiate noise sensitivity and MCS as different entities. Overlaps have been found in the characteristics of persons reporting chemical and noise sensitivities. For MCS a large number of mechanisms have been presented, while there are only a few studies on the mechanism of noise sensitivity. To evaluate the similarities and differences in their mechanisms more studies are needed. The genetic predisposition for MCS and noise sensitivity should be studied further to see whether there is a shared genetic predisposition. Further studies are needed to investigate whether noise sensitivity and MCS are a part of the general environmental sensitivity.