Symptoms guide · 7 min read
Concussion Symptoms: The Complete Checklist
Concussion symptoms are famously inconsistent: two people can take the same hit and have completely different experiences — and some of the most important symptoms don't show up right away. Here's the full picture, including the delayed symptoms and eye symptoms people most often miss.
Concussion symptom checklist
Physical: headache or pressure in the head, dizziness, balance problems, nausea or vomiting, sensitivity to light and noise, neck pain, fatigue, visual changes.
Cognitive: brain fog, feeling "slowed down," trouble concentrating, memory problems, difficulty finding words, taking longer to answer questions.
Emotional: irritability, anxiety, sadness, feeling more emotional than usual.
Sleep: sleeping much more or less than usual, trouble falling asleep, non-restorative sleep.
Clinicians often quantify these with the Post-Concussion Symptom Scale (PCSS) — a 22-item, 0–6 severity checklist. Tracking your own daily total is a genuinely useful way to see recovery trends and share objective information with your clinician.
How long after hitting your head can concussion symptoms start?
Usually within minutes to hours — but concussion symptoms can absolutely be delayed by 24–72 hours, and occasionally longer. Delayed onset happens because early adrenaline masks symptoms, because some problems (vestibular, visual) only reveal themselves when you return to demanding environments, and because sleep disruption compounds over days. A person who "felt fine" after a car crash or a hard tackle and feels foggy two days later is a textbook presentation, not an unusual one.
Delayed concussion symptoms to watch for
- Headache that builds over days rather than improving
- Fog, irritability, or fatigue emerging when returning to work, school, or screens
- Dizziness in busy environments (grocery stores are the classic trigger)
- Sleep disturbance beginning several nights after the injury
Important distinction: delayed worsening — severe escalating headache, repeated vomiting, confusion, weakness, slurred speech, seizures, or unusual drowsiness — is an emergency. Those aren't "delayed concussion symptoms"; they can signal bleeding and warrant immediate emergency care.
Concussion eye symptoms
The visual system is heavily involved in concussion, and eye symptoms are among the most common lingering complaints: blurred or double vision, eye strain and fatigue with screens or reading, trouble shifting focus between near and far, losing your place while reading, headaches triggered by visual work, and light sensitivity. The usual culprits — convergence insufficiency and oculomotor dysfunction — don't show up on a standard eye chart, but a neuro-optometrist or vision therapist can identify and treat them effectively.
How long do concussion symptoms last?
Most people recover in two to four weeks (children and teens often need the full four). Symptoms lasting beyond a month suggest post-concussion syndrome, which responds best to targeted, active treatment rather than more waiting. Persistent dizziness, visual strain, or exertion intolerance are each strong reasons to see a concussion specialist.
Find a concussion specialist near you
Search 3,214 verified concussion clinics and specialists across all 50 states — filter by services like vestibular therapy, vision therapy, and neuropsychology.
Frequently asked questions
Can concussion symptoms be delayed?
Yes. While most symptoms appear within minutes to hours, delayed symptoms 24–72 hours after the injury are common — often unmasked by returning to work, school, screens, or busy environments. Rapidly worsening symptoms, however, are an emergency.
What are concussion eye symptoms?
Blurred or double vision, eye strain with screens or reading, difficulty changing focus, losing your place while reading, visual-triggered headaches, and light sensitivity. Convergence insufficiency is a frequent, treatable cause identified by neuro-optometrists.
How long do concussion symptoms last?
Two to four weeks for most people; children and teens often take longer. Symptoms beyond a month indicate possible post-concussion syndrome and warrant evaluation by a concussion specialist.
Educational content only — not a substitute for professional medical advice, diagnosis, or treatment. Reviewed by Jon MacKay, PharmD, BCACP against current clinical guidance; last updated July 2026.