A chiropractic adjustment, or spinal manipulative therapy, involves the application of a controlled force to a spinal joint to restore proper function and mobility. Many people seek this treatment for pain relief, but they often wonder if the manipulation can result in sickness or feeling generally unwell afterward. Most post-treatment reactions are mild, temporary, and represent the body’s normal physical response to a mechanical change. Serious complications are extremely infrequent, and understanding the difference between a normal reaction and a genuine concern is important.
Common Post-Adjustment Aches and Pains
The most frequent physical responses following a spinal manipulation are mechanical reactions within the musculoskeletal system, not signs of illness. Many patients report temporary soreness or stiffness in the treated area, often described as feeling similar to muscle discomfort after a moderate workout. This sensation occurs because the adjustment stretches and moves muscles, ligaments, and tendons that may have been restricted.
When joints are realigned, previously underutilized muscles may be stimulated, causing muscle fatigue as they adapt to the body’s new, corrected posture. The controlled force used also stimulates an inflammatory response at the cellular level, which is part of the body’s natural healing process.
A mild, temporary headache may also occur, especially after adjustments to the neck or upper back region. This type of headache is related to the sudden release of built-up muscle tension in the cervical spine. These symptoms are localized and should resolve quickly, usually within 24 to 48 hours. Maintaining hydration and using ice or heat, as recommended by the practitioner, can help mitigate this temporary discomfort.
Explaining Transient Systemic Reactions
Beyond simple muscle soreness, some patients experience systemic reactions that they may confuse with being sick, such as dizziness, nausea, or general fatigue. These symptoms are not caused by infection but stem from temporary changes in nervous system function and metabolic activity.
Dizziness or lightheadedness can occasionally occur immediately following an adjustment, particularly if the neck was treated. This reaction is attributed to the nervous system temporarily adjusting to the sudden change in joint position and the resulting altered input to the vestibular system. This temporary sensation is usually short-lived and resolves within minutes.
Nausea or an upset stomach is another reported systemic reaction linked to the vagus nerve. The vagus nerve plays a significant role in regulating involuntary functions, including heart rate and digestion. Adjustments, particularly in the upper cervical and thoracic spine, can influence the autonomic nervous system, which may temporarily affect vagus nerve signaling and manifest as a feeling of queasiness.
Some individuals report mild, generalized discomfort that feels like the start of a cold or the flu, including fatigue and body aches. This is sometimes referred to as a “healing crisis” or “toxic release” phenomenon. The theory suggests that long-held tension and inflammation can cause metabolic waste products, such as lactic acid, to be stored in muscle tissue.
When the adjustment releases this physical tension, these stored metabolic byproducts are flushed into the bloodstream for elimination. The body’s temporary effort to process and eliminate this sudden influx of waste can lead to the transient flu-like symptoms. The actual mechanism is the body’s non-infectious response to chemical and neurological changes. These systemic reactions are generally mild and self-limiting, typically subsiding within a day or two.
Serious Adverse Events and Safety Protocols
While the majority of post-adjustment symptoms are mild and transient, extremely rare, severe adverse events have been documented, primarily in association with neck manipulation. The most discussed risk involves a vertebral artery dissection, which is a tear in one of the arteries that supplies blood to the brain, potentially leading to a stroke. Other severe events, such as a worsening of a disc herniation or cauda equina syndrome, are also extremely infrequent.
Large-scale studies consistently show that the incidence of a severe adverse event is remarkably low. The estimated risk of a serious complication following cervical spine manipulation is minimal.
Patient Screening
To mitigate these minimal risks, licensed practitioners follow established safety protocols that begin with a comprehensive patient screening. Before any treatment, a thorough medical history is taken, and a physical examination is performed to identify any contraindications, such as certain spinal or vascular conditions. This initial assessment determines if the patient has any pre-existing pathology that could make manipulation unsafe for them.
Recognizing Red Flags
Patients are also advised on specific red flag symptoms that necessitate immediate medical attention, as these indicate a problem beyond a normal post-adjustment reaction. These symptoms include a sudden, severe headache unlike any experienced before, rapidly worsening numbness or tingling, difficulty with speech, or difficulty walking. Open communication with the practitioner regarding any pre-existing conditions or unusual symptoms is the most effective safety measure a patient can take.