If you experience a sense of dizziness in a crowded mall, movie theater, or sports venue, then you may be experiencing Chronic Subjective Dizziness (CSD), described by experts as “a feeling of imbalance, lightheadedness, or spinning while standing still.”

Recently, researchers at the University of Pennsylvania School of Medicine determined that CSD, which affects at least 3 million people in the U.S., may be related to anxiety disorders, migraine headaches, mild traumatic brain injuries (TBI), and problems in the autonomic nervous system, that part of the nervous system that controls your involuntary physical reactions.

“Patients with CSD experience persistent dizziness not related to vertigo,” says Jeffrey P. Staab, MD, MS, including “imbalance, and hypersensitivity to motion, which is heightened in highly visual settings, such as walking in a busy store or driving in the rain.”

Undertaken by Pennsylvania School of Medicine Assistant Professor Staab and Associate Professor Michael J. Ruckenstein, MD, the research involved 345 men and women age 15 to 89 who had dizziness for three months or longer due to unknown causes. Of the participants, all but six were diagnosed as having psychiatric (for example, anxiety disorders) or neurologic (e.g., traumatic brain injury) conditions.

Bottom line: Although it’s often assumed that vertigo or dizziness is related to an inner-ear condition,  it has been difficult for doctors to determine a cause for CSD, an ongoing symptom not related to an inner-ear function. However, they now have new possible causes to consider, which means that if the underlying condition can be treated, the CSD may be resolved as well.

For further information:  “Expanding the Differential Diagnosis of Chronic Dizziness,“, Jeffrey P. Staab, MD, MS, and Michael J. Ruckenstein, MD, Archives of Otolaryngology – Head & Neck Surgery, vol 133, no 2, February 2007.