Sleeping on an Airplane: It’s All about Blood Flow

This week, the I Spy Physiology blog answers a reader question: Why is it hard to sleep upright on an airplane? Having trouble sleeping when traveling on an airplane or by train or car may not be just because of the change in air pressure or the motion of the vehicle. Your circulation—or lack of … Continue reading Sleeping on an Airplane: It’s All about Blood Flow

Circulatory Failure: When Blood Pressure Dips Too Low

We often hear about high blood pressure and how it can be dangerous to health, but low blood pressure isn’t talked about as much. For most people, a blood pressure reading lower than 90/60 mmHg may cause lightheadedness but otherwise is unlikely to cause long-term harm. However, in cases of severe disease or major injury, … Continue reading Circulatory Failure: When Blood Pressure Dips Too Low

In Hot Water

This week, the I Spy Physiology blog answers a reader question: Why do we get dizzy when getting out of a hot tub? There may not be a better way to chase away the winter "blahs" than soaking in the hot tub or standing under a steaming shower. However, sometimes, after a lengthy soak or … Continue reading In Hot Water

Feeling Lightheaded after Exercise? Use the Heart in Your Legs!

Do you ever get lightheaded or feel a little dizzy after hard exercise? Maybe you have felt a little bit of “tunnel vision” after a hard sprint or when you stand up in the first hour after a long training session? This is a surprisingly common occurrence in healthy people, as recently reviewed in the … Continue reading Feeling Lightheaded after Exercise? Use the Heart in Your Legs!