When the body experiences physical stress, major dietary changes, illness, hormonal fluctuations, or rapid weight reduction, more hairs can prematurely enter the telogen phase
European Journal of Clinical Nutrition, 72 (1), 105
and caution is needed in patients with severe gastrointestinal disease
Acknowledgements This work was supported in part by US National Institutes of Health (NIH)/National Institute of Mental Health grant R03MH076449 (D.L.W.) and by NIH/National Institute of Allergy and Infectious Diseases (NIAID) grant R01AI065622 (D.L.W.), and in part by the NIH Roadmap for Medical Research Molecular Libraries Program
Dehydration from gastrointestinal side effects such as nausea, vomiting, or diarrhea can lower blood volume and blood pressure, leading to lightheadedness when standing or moving quickly