Phlegm is the thick mucus produced by the respiratory tract, typically associated with illnesses like a cold or the flu. While phlegm itself does not directly cause back pain, the underlying conditions that produce it and the violent actions taken to expel it can result in back discomfort. The coughing reflex, which clears the airways, is the primary mechanical link between a respiratory illness and back pain. Another connection lies in the body’s inflammatory response to the infection generating the phlegm.
How Forceful Coughing Causes Back Strain
A forceful cough is a sudden, powerful physical event engaging muscles throughout the torso. The action involves a rapid, coordinated contraction of the abdominal muscles, the diaphragm, and the intercostal muscles of the rib cage. This contraction compresses the abdominal contents, leading to a sudden increase in intra-abdominal pressure (IAP). This pressure spike creates an overloading force on the spinal column and its supporting structures.
Repetitive coughing can lead to muscle strain, particularly in the lower back’s erector spinae muscles or the muscles surrounding the rib cage. This overuse causes microscopic tears in the muscle fibers, resulting in soreness, stiffness, and muscle spasms. For those with pre-existing spinal issues, such as a herniated disc or spinal stenosis, the sudden pressure from a cough can exacerbate their condition. The increased IAP pushes against the spinal discs, which can intensify nerve compression and cause radiating pain.
Systemic Inflammation and Associated Conditions
Beyond the mechanical strain of coughing, the underlying illness producing the phlegm can cause back pain through systemic inflammation. Severe respiratory infections, such as bronchitis, influenza, or pneumonia, trigger an immune response. This inflammation can manifest as myalgia, or muscle aches, throughout the body, including the back. These aches result from chemical signals released by the immune system, independent of any physical coughing effort.
Another cause is pleurisy, where the pleura (the thin lining surrounding the lungs and chest wall) becomes inflamed. Since the pleura is supplied with nerves, this inflammation causes a sharp, stabbing chest pain that worsens with deep breaths or coughing. This pain often radiates or is “referred” to the upper back or shoulder blade area. A phlegm-producing cough can thus trigger back pain not just from muscle strain, but from the inflamed lining of the lungs.
Relief Strategies and When to Seek Medical Help
To manage pain from a persistent, phlegm-producing cough, strategies should focus on reducing the cough’s severity and supporting affected muscles. Using a humidifier or increasing fluid intake helps thin the mucus, making the cough less forceful and more productive. Over-the-counter cough suppressants reduce the frequency of dry coughing fits, while nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, control muscle inflammation and pain.
When coughing, stabilize your torso by bracing yourself on a stable object or hugging a pillow against your abdomen to redistribute the force. For muscle soreness, applying heat (such as a warm compress or bath) helps relax strained muscles, while cold packs reduce local inflammation. Gentle stretching and movement prevent stiffness, but excessive activity should be avoided while the muscle is healing.
Seek medical attention if back pain is accompanied by warning signs, as these may indicate a serious underlying infection or spinal issue. Immediate consultation is necessary if you experience:
- A high fever.
- Difficulty breathing or persistent shortness of breath.
- Pain that radiates down the legs, new numbness, or tingling.
- Coughing up blood.
If the back pain does not subside shortly after the respiratory illness has cleared, a doctor should evaluate the spine for potential structural damage.