Thunderclap Headache - Symptoms & Causes

What is a thunderclap headache?

A thunderclap headache is a severe, sudden headache that reaches its peak intensity within seconds to a minute. This type of headache can be alarming due to its sudden onset and extreme pain.

Thunderclap headaches often indicate a serious underlying condition, such as bleeding in the brain or other neurological emergencies and should always be treated as a medical emergency.

What are the types of thunderclap headaches?

Thunderclap headaches can be classified based on their underlying causes:

• Primary thunderclap headache occurs without an identifiable underlying cause. These are rare but can be benign.
• Secondary thunderclap headache is caused by serious underlying conditions such as:
  • Subarachnoid haemorrhage (bleeding in the brain)
  • Reversible cerebral vasoconstriction syndrome (RCVS)
  • Cerebral venous sinus thrombosis (blood clot in the brain)
  • Cervical artery dissection (tear in the neck artery)
  • Pituitary apoplexy (bleeding or impaired blood supply in the pituitary gland)
  • Hypertensive crisis (extremely high blood pressure)

What are the symptoms of a thunderclap headache?

Symptoms of a thunderclap headache include:

• Sudden, severe headache reaching maximum intensity within seconds to a minute
• Pain often described as the worst headache ever experienced
• Nausea and vomiting
• Stiff neck
• Sensitivity to light (photophobia)
• Visual changes such as blurred vision or double vision
• Confusion or altered mental status
• Seizures or loss of consciousness in severe cases

When to seek medical attention?

Due to the potential severity of the underlying causes, seeking immediate medical attention is crucial if you experience a thunderclap headache. You should seek medical attention immediately if:

• You experience a sudden, severe headache that reaches peak intensity within seconds to a minute
• The headache is accompanied by symptoms such as nausea, vomiting, stiff neck, or visual disturbances
• You have a history of headaches, but this headache is significantly different in intensity and onset

When to visit urgent care centre?

Visit an urgent care centre immediately if:

• You have a thunderclap headache, as it can be a sign of a life-threatening condition
• The headache is accompanied by neurological symptoms such as confusion, weakness, numbness, or difficulty speaking
• You experience seizures, loss of consciousness, or any other severe symptoms

The sooner the underlying cause is addressed, the better. Early treatment can significantly improve recovery and prevent long-term complications.

What causes a thunderclap headache?

Thunderclap headaches are caused by various serious and potentially life-threatening conditions, including:

• Subarachnoid haemorrhage, which refers to bleeding in the space between the brain and the surrounding membrane. This is a medical emergency requiring immediate attention.
• Aneurysm rupture, which refers to weak bulges in blood vessels rupturing.
• Reversible cerebral vasoconstriction syndrome (RCVS), which refers to temporary narrowing of blood vessels in the brain.
• Cerebral venous sinus thrombosis, which refers to a blood clot in the brain's venous sinuses.
• Cervical artery dissection, which refers to a tear or dissection of one of the arteries supplying blood to the brain.
• Pituitary apoplexy, which refers to bleeding or impaired blood supply in the pituitary gland.
• Hypertensive crisis, which refers to extremely high blood pressure causing complications.
• Preeclampsia or eclampsia, which refer to pregnancy complications that involve sudden changes in blood pressure, potentially leading to thunderclap headaches.
• Meningitis, which refers to inflammation of the membranes surrounding the brain and spinal cord.

What are the complications of thunderclap headache?

The complications of a thunderclap headache arise not from the headache itself, but from the underlying medical condition that caused it. Because a thunderclap headache can be a sign of a serious condition, the potential complications can be severe if left untreated:

Complications from bleeding in the brain:

• Brain damage. Bleeding in the brain (subarachnoid hemorrhage) can damage brain tissue if not treated promptly. This damage can lead to long-term problems like cognitive impairments, paralysis, or even coma.
• Hydrocephalus. This is a condition where cerebrospinal fluid (CSF) builds up in the brain, causing pressure and potentially leading to further brain damage.
• Seizures. Bleeding in the brain can increase the risk of seizures, which require immediate medical attention.
• Death. In severe cases, bleeding in the brain can be fatal, highlighting the importance of seeking immediate medical attention for a thunderclap headache.

Complications from ruptured aneurysms:

• Stroke. A ruptured aneurysm can block blood flow to parts of the brain, leading to a stroke. Symptoms of stroke can include weakness, numbness, or difficulty speaking.
• Coma. In severe cases, a ruptured aneurysm can lead to coma.
• Death. Ruptured aneurysms can be life-threatening, emphasising the urgency of seeking medical attention for a thunderclap headache.

Complications from other causes:

• Meningitis complications. If meningitis is the cause of the thunderclap headache, complications can include hearing loss, learning disabilities, or even brain damage if not treated promptly.
• Long-term effects of high blood pressure. If a thunderclap headache is caused by a hypertensive crisis (sudden, severe increase in blood pressure), long-term complications of high blood pressure can develop if not managed effectively.

Early diagnosis and treatment of the underlying cause of a thunderclap headache is crucial to prevent these complications. If you experience a sudden, severe headache, proceed to the nearest urgent care centre.

How do you prevent thunderclap headaches?

There is no guaranteed way to completely prevent thunderclap headaches because they arise from various underlying medical conditions. However, focusing on managing potential risk factors and maintaining a healthy lifestyle can contribute to a lower risk of developing some conditions that might cause thunderclap headaches:

• Regularly monitor and manage blood pressure to prevent hypertensive crises.
• These can increase the risk of vascular problems leading to thunderclap headaches.
• While not always preventable, taking precautions to minimise head injuries (wearing seatbelts, helmets during sports) can be helpful.
• Regular medical check-ups to identify and manage conditions that could cause thunderclap headaches.
• Maintain a healthy lifestyle with a balanced diet, regular exercise, and stress management.