A headache that significantly lessens or resolves when lying down is known as a positional or orthostatic headache. This distinct type of head pain provides important clues about its underlying cause, pointing to specific physiological mechanisms.
Understanding Positional Headaches
Positional headaches arise from changes in pressure within the cerebrospinal fluid (CSF) system. CSF surrounds the brain and spinal cord, cushioning and protecting these delicate structures.
When an individual is upright, gravity naturally affects the distribution of CSF. If the volume or pressure of CSF is lower than normal, being in an upright position can cause the brain to sag slightly within the skull. This downward displacement pulls on pain-sensitive structures, such as the meninges (the membranes covering the brain and spinal cord), nerves, and blood vessels, leading to pain. Lying flat allows the CSF to redistribute, reducing the traction on these sensitive structures and alleviating the headache.
Primary Causes of Headaches That Improve When Lying Down
The most common cause of a headache that improves when lying down is a reduction in cerebrospinal fluid (CSF) volume or pressure, often due to a CSF leak. This condition is broadly termed intracranial hypotension. These leaks typically occur in the spine, allowing CSF to escape from the dura mater, the tough outer membrane encasing the brain and spinal cord.
Spontaneous Intracranial Hypotension (SIH) accounts for many cases where a CSF leak occurs without a clear cause. SIH can result from various types of dural tears, including those from a calcified ventral osteophyte or leaking nerve root diverticula. Minor trauma, such as a sudden sneeze, strenuous activity, or a fall, can sometimes trigger a leak in individuals with a predisposition, such as those with underlying connective tissue disorders. The incidence of SIH is estimated to be around 5 per 100,000 people, with a female predominance and an average age of onset between 40 and 45 years.
Another significant cause is Post-Dural Puncture Headache (PDPH), which is a common complication following medical procedures that involve puncturing the dura mater. These procedures include lumbar punctures (spinal taps) or epidural anesthesia. The headache arises because CSF leaks through the puncture site, leading to decreased intracranial pressure. PDPH typically manifests within 24 to 48 hours after the procedure, though it can sometimes occur later.
Accompanying Symptoms and When to Seek Medical Attention
Headaches that improve with lying down are often accompanied by other symptoms. These may include neck pain or stiffness, which can be described as a rigid sensation, and nausea, sometimes with vomiting. Individuals might also experience dizziness, balance problems, or vertigo.
Changes in hearing, such as ringing in the ears (tinnitus), muffled hearing, or hearing loss, are also frequently reported. Visual disturbances like blurred or double vision can occur, along with sensitivity to light (photophobia) or sound (phonophobia). Additionally, fatigue, brain fog, and pain between the shoulder blades or in the arms can be present.
Seeking medical attention is advisable if you experience headaches that worsen when upright and improve when lying down. It is especially important to consult a healthcare provider if these headaches are persistent or worsening. Immediate medical evaluation is necessary if new neurological symptoms develop, such as significant changes in vision, speech, or balance, or if the headache occurs after a recent medical procedure like a spinal tap. Any headache that significantly impacts daily life or is accompanied by severe symptoms warrants professional assessment.
Diagnosis and Treatment Options
Diagnosing headaches that improve with lying down typically involves a comprehensive approach. A healthcare provider will begin by taking a detailed medical history, focusing on the characteristics of the headache and any recent medical procedures or injuries. A physical examination helps assess neurological function and identify any signs of intracranial pressure changes.
Imaging studies are crucial for confirming the diagnosis and locating the source of a cerebrospinal fluid (CSF) leak. Magnetic Resonance Imaging (MRI) of the brain is often performed to look for signs of intracranial hypotension, such as brain sagging or diffuse meningeal enhancement. MRI of the spine can also be used to identify potential leak areas. If a leak is suspected, a CT myelography, which involves injecting contrast dye into the spinal canal, is considered the gold standard for pinpointing the exact site of the CSF leak. Digital subtraction myelography is increasingly used for high-flow leaks.
Treatment options for these headaches range from conservative measures to more interventional procedures. Initial conservative management often includes strict bed rest, increased fluid intake, and caffeine consumption, which can sometimes help alleviate symptoms. However, these methods are not always effective in sealing the leak itself.
For persistent symptoms, an epidural blood patch (EBP) is a common and often effective treatment. This procedure involves taking a small amount of the patient’s own blood and injecting it into the epidural space around the spinal cord, ideally at or near the leak site. The injected blood forms a clot, which can seal the dural tear and increase CSF pressure, providing relief.
The success rate for EBPs in post-dural puncture headaches is high, and is also effective for spontaneous CSF leaks. In cases where the leak is complex or unresponsive to blood patches, surgical options may be considered to directly repair the dural tear.