The brain, spinal cord, and peripheral nerves form the body’s communication and control system. Together they regulate movement, sensation, memory, language, behavior, sleep, balance, and many automatic functions such as breathing and heart rate.
How the Nervous System Works
The central nervous system consists of the brain and spinal cord. The peripheral nervous system includes nerves that carry information between the central nervous system and the rest of the body. Some nerves control voluntary movement and sensation, while the autonomic nervous system helps regulate involuntary functions such as heart rate, digestion, sweating, and blood pressure.
Common Brain and Nervous System Conditions
- Stroke and transient ischemic attack (TIA) — caused by disruption of blood flow to part of the brain.
- Migraine and other headache disorders — may cause headache, nausea, sensitivity to light or sound, and sometimes neurological symptoms.
- Epilepsy — a neurological disorder associated with recurrent unprovoked seizures.
- Multiple sclerosis (MS) — an immune-mediated condition affecting the brain and spinal cord.
- Parkinson’s disease — a progressive neurological condition that can affect movement, balance, sleep, and other functions.
- Alzheimer’s disease and other dementias — conditions that can affect memory, thinking, communication, and daily functioning.
- Peripheral neuropathy — damage to peripheral nerves that may cause numbness, tingling, pain, or weakness.
- Meningitis and encephalitis — inflammation involving tissues around the brain or the brain itself, sometimes caused by infection.
- Brain and spinal cord tumors — abnormal growths that may be benign or malignant and can cause symptoms depending on their location.
Possible Neurological Symptoms
Symptoms depend on which part of the nervous system is affected. They may include:
- Weakness, numbness, or tingling
- Tremor or problems with movement and coordination
- Loss of balance or repeated falls
- Seizures or episodes of altered awareness
- Persistent or unusual headaches
- Changes in vision, speech, hearing, or sensation
- Memory problems, confusion, or changes in thinking
- Nerve pain or burning sensations
- Changes in bladder or bowel control
These symptoms can have many causes and do not necessarily mean that a person has a serious neurological disease.
Emergency Warning Signs
Seek emergency medical care immediately for sudden facial drooping, weakness or numbness on one side of the body, sudden difficulty speaking or understanding speech, sudden severe loss of balance, or sudden vision loss. These can be signs of a stroke.
Emergency assessment is also important for a first seizure, a seizure lasting several minutes or repeated seizures without recovery, sudden loss of consciousness, a sudden extremely severe headache, or new neurological symptoms following a significant head or spinal injury.
Diagnosis
Assessment usually begins with a medical history and neurological examination. Depending on the symptoms, testing may include blood tests, CT or MRI scans, electroencephalography (EEG), nerve conduction studies, lumbar puncture, or other specialized investigations.
Treatment
Treatment depends on the underlying condition. It may include medication, surgery, rehabilitation, physical or occupational therapy, speech and language therapy, psychological support, or changes to daily routines. Some neurological conditions can be cured or resolve, while others require long-term treatment and monitoring.
When to Seek Medical Advice
Contact a healthcare professional if neurological symptoms are new, persistent, recurrent, worsening, or interfering with everyday activities. Early assessment can be important because some neurological conditions respond better when treatment begins promptly.
Sources and Further Reading
- National Institute of Neurological Disorders and Stroke (NINDS)
- MedlinePlus: Neurologic Diseases
- CDC: Stroke
Last reviewed: 4 September 2026. This page provides general health information and does not replace individual medical advice.