Blood pressure (BP) is the force of blood pushing against the walls of the arteries as the heart pumps blood throughout the body. A forceful cough is a dramatic physical event that necessarily impacts internal body pressures. While the immediate effect of coughing on blood pressure is measurable and significant, the long-term impact on sustained high blood pressure, or hypertension, is a different matter. This article explores the immediate, transient effects of coughing on BP and distinguishes them from chronic conditions where coughing and high blood pressure co-exist.
Temporary Blood Pressure Spikes During Coughing
A forceful cough generates rapid pressure changes within the chest cavity. The act begins with a deep breath followed by a forced expiration against a closed windpipe, similar to the Valsalva maneuver. This causes a sudden contraction of the abdominal and chest muscles, creating intrathoracic pressures as high as 250 to 450 millimeters of mercury (mmHg) and intra-abdominal pressures around 100 mmHg.
This intense pressure surge momentarily compresses the large veins returning blood to the heart, significantly restricting the heart’s ability to fill with blood. The resulting drop in venous return causes an immediate, transient decrease in cardiac output and, consequently, a brief dip in blood pressure. However, the pressure inside the chest also squeezes the aorta, creating an initial, very high spike in arterial pressure.
As the cough concludes and the high intrathoracic pressure is released, the restricted blood rushes back into the heart and circulation, causing a sharp, temporary rebound known as the blood pressure overshoot. This rapid sequence of pressure fluctuations—dip, spike, and overshoot—is quickly sensed by the body’s regulatory systems, particularly the baroreceptors. These systems work to restore blood pressure to its baseline level within a few heartbeats.
Does Chronic Coughing Lead to Sustained High Blood Pressure?
The transient spikes in blood pressure caused by a single cough do not translate into sustained, chronic hypertension. Chronic hypertension is defined by consistently elevated blood pressure readings over time, often resulting from factors like arterial stiffness or kidney dysfunction. The body’s built-in regulatory mechanisms, such as the baroreflex, are highly effective at normalizing the pressure fluctuations following a cough, preventing lasting elevation.
However, a strong association exists between chronic coughing and a higher prevalence of hypertension, though the relationship is not a simple cause-and-effect. Patients suffering from a chronic cough, defined as one lasting eight weeks or longer, are statistically more likely to be hypertensive than the general population. One study indicated that a quarter of chronic cough patients were hypertensive, suggesting a link beyond mere coincidence.
The mechanism for this association may involve the repeated stimulation of the autonomic nervous system (ANS) that occurs with frequent coughing episodes. This stimulation causes repeated spikes in heart rate and blood pressure. The persistent stress on the ANS may contribute to autonomic imbalance or dysfunction, which can indirectly promote the development of sustained hypertension over many months or years.
When Coughing Signals a Heart or Lung Issue
Instead of coughing causing chronic high blood pressure, both symptoms often appear together as a sign of a shared, underlying health problem. One of the most common connections is with Congestive Heart Failure (CHF), a condition where the heart cannot pump blood efficiently. Long-standing hypertension is a leading cause of CHF, and in turn, CHF can cause a persistent cough, especially one that is wet or worsens when lying down, due to fluid backing up into the lungs.
Pulmonary Arterial Hypertension (PAH) is high blood pressure in the arteries of the lungs, distinct from systemic hypertension. PAH symptoms can include a persistent, dry cough because the high pressure and potential enlargement of the pulmonary artery can irritate nerves in the chest. A cough in this context is a symptom of the circulatory stress, not a cause of the high pressure.
Certain medications prescribed to treat high blood pressure, Angiotensin-Converting Enzyme (ACE) inhibitors, are a well-known cause of a dry, chronic cough. In this scenario, the high blood pressure is being treated, and the medication itself is the direct cause of the cough. Any person experiencing a persistent cough alongside consistently high blood pressure readings, or other symptoms like shortness of breath or ankle swelling, should consult a physician for a full evaluation.