“I wanted to be left alone, so whenever someone came close, I started coughing.” That sounds like a pretty aggressive way to establish social distancing, but clearly an effective strategy.
What is a cough, exactly? And when is cough more than just a cough?
Basically, a cough consists of three main parts:
Stimulation of respiratory tract receptors triggers a sudden intake of breath.
The chest and abdominal muscles tighten while the glottis (vocal cords within the larynx) is closed, creating a sharp rise in chest (intrathoracic) pressure.
Glottis suddenly opens, with a sudden noisy rush of air, heard as the cough.
The purpose of a cough is readily evident: Coughing allows the body to expel foreign particles, irritants, microbes (including, famously, coronavirus), mucus, and bacteria.
Coughing can be quite unpleasant and often is associated with serious underlying disease; unsurprisingly, coughing is one of the most common presenting complaints to primary care doctors. While many causes are short-lived (< 3 weeks), smoking, asthma, bronchitis, and stomach reflux (GERD) may cause chronic coughs for months or even years.
Coughing itself can cause complications, some occasionally quite serious. A recent review in The American Journal of Medicine (Schatter A: AMJ 2020; 133:544-551) cataloged a wide range of cough-induced complications. Among the most common serious issues, violent coughing may lead to rib fractures, chest pain, pneumothorax, hernias (from the rapid increase in intra-abdominal pressure), rupture of the spleen, fainting (syncope), headache, sleep deprivation, and stress urinary incontinence (mostly in women).
Eye complications of coughing are pretty common but usually limited to subconjunctival hemorrhage — bleeding on the ocular surface which often looks quite alarming, but which rarely causes any ongoing problems. However, more extensive bleeding may occur around the eyelids (the “panda sign”), with pretty scary bruising which lasts for several weeks.
Inside the eye (supra-choroidal hemorrhage and Valsalva retinal hemorrhage). Air may travel from the respiratory passages into the eye socket (orbital emphysema). Acute retinal detachment has been reported with violent coughing.
Violent coughing often causes photopsia — transient visual disturbances from the ocular structures basically being shaken up. These are often experienced as seeing bright lights or bright spots and are usually short-lived without long-term consequences.
So, next time someone asks you to “cough it up”, maybe keep it down, or at least greater than 6 feet away.
Benjamin H. Ticho, MD