The Short Answer Educational content only. Any suspected concussion warrants medical evaluation. Persistent sensory symptoms after concussion warrant assessment by the appropriate specialist, an audiologist or ENT for hearing and sound symptoms, a neuro-optometrist or ophthalmologist for visual and eye symptoms, and a physician or neurologist to coordinate care. Consult a concussion-experienced clinician for individualized care. Anosmia persists after concussion because the delicate olfactory nerve fibers are sheared where they pass through the skull base during the injury, cutting the connection between the nose and the brain (Proskynitopoulos et al., 2016). Anosmia is the loss of the sense of smell. The olfactory nerve fibers travel from the nose through tiny holes in a thin plate of bone at the skull base, the cribriform plate, and the shearing forces of head trauma can tear them there. Because these fibers regenerate slowly and imperfectly, and sometimes not at all, smell loss can be prolonged or permanent. It also blunts flavor, since most of what we call taste is smell. Smell training can aid recovery in some cases, and safety adjustments for hazards that smell would warn of are essential while smell is absent. Olfactory nerve fibers are sheared at the skull base during head trauma. These fibers regenerate slowly and imperfectly, so loss can be lasting. Smell training can aid recovery, and safety adjustments are essential. What Anosmia Is Anosmia is the complete loss of the sense of smell, and its partial form, reduced smell, is called hyposmia. It is one of the more common sensory consequences of head injury and often goes unrecognized at first, because it is noticed indirectly through the loss of flavor in food rather than as an obvious symptom. People with anosmia describe food as bland or tasteless, cannot detect odors like smoke or spoiled food, and lose the emotional and memory associations that smells carry. Anosmia after head injury can be complete or partial, and it can appear immediately or become apparent during recovery. How Concussion Damages the Olfactory Nerve The sense of smell depends on a uniquely vulnerable anatomy. Olfactory receptor neurons sit high in the nasal cavity, and their fine nerve fibers pass upward through many tiny perforations in the cribriform plate, a thin sheet of bone at the base of the skull, to reach the olfactory bulb in the brain. During head trauma, the movement of the brain relative to the skull creates shearing forces at exactly this point, and the delicate fibers passing through the bone are stretched and torn where they cross it. This severs the connection between the smell receptors in the nose and the brain. Because the damage is at the point where the nerve threads through bone, even a concussion without a skull fracture can cause it. The olfactory system's vulnerability at the cribriform plate is why smell loss is a recognized consequence of head injury across a range of severities. Why It Can Be Prolonged or Permanent The olfactory system has an unusual capacity for regeneration, more than most of the nervous system, because olfactory receptor neurons can renew and their fibers can attempt to regrow through the cribriform plate. This is why some people recover smell over months to a few years. Yet the regeneration is slow, incomplete, and unpredictable. Scarring at the cribriform plate can block regrowing fibers, and fibers that do regrow may not reconnect correctly. As a result, recovery ranges widely: some people regain smell, some improve partially, and some have permanent loss. The degree of initial damage largely determines the outcome. Symptom Presentation Complete or partial loss of the sense of smell Food tasting bland or flavorless despite intact basic taste Inability to detect smoke, gas, or spoiled food Loss of the emotional and memory associations of smells Onset immediately after injury or noticed during recovery Reduced appetite and enjoyment of eating Sometimes distorted smell as fibers regenerate Assessment An ENT specialist assesses anosmia with formal smell testing that measures the ability to detect and identify odors, confirming and quantifying the loss, since self-report underestimates it. The assessment distinguishes smell loss from nasal blockage, which has other causes, and considers imaging of the olfactory structures when indicated. Because smell loss blunts flavor, the assessment also clarifies that intact basic taste is being masked by absent smell. A physician coordinates care and addresses the safety implications of absent smell. Treatment Approach Smell training is the main active treatment and can aid recovery in some people. It involves deliberately and repeatedly smelling a set of distinct scents, such as rose, lemon, clove, and eucalyptus, twice daily over months, to stimulate and guide the regenerating olfactory system. Consistency over a prolonged period is what gives it a chance to help, and it works best started earlier rather than later. Not everyone recovers, but smell training improves the odds in appropriate cases. Safety adjustments are essential while smell is absent, because smell warns of hazards. Installing and maintaining smoke and gas detectors, being careful with food expiration dates and cooking, and using electric rather than gas appliances where possible protect against dangers that smell would otherwise flag. Support for the loss of enjoyment in eating, and attention to appetite and nutrition, matter too, since food becomes less rewarding. A physician monitors recovery over the extended timeline that olfactory regeneration follows. Sensory symptoms after concussion improve faster when the nervous system is regulated and the neck and autonomic system are addressed alongside specialist care. Start your 3-day free trial to build a supportive daily routine. Supporting Mobility Routine JME 155 Diaphragmatic breathing lowers the sympathetic drive that amplifies sensory sensitivity and steadies the nervous system. Ten slow breaths, several times daily. JME 14 Chin tucks reduce upper cervical tension that feeds headache, dizziness, and sensory overload. Ten repetitions with 5-second holds. JME 1 Cervical rotation restores segmental mobility and supports blood flow through the vertebral arteries to the brain. Ten repetitions per direction. JME 15 Cervical lateral flexion addresses side-bending restriction that sustains neck tension and sensory strain. Ten repetitions per side. JME 16 Cervical flexion and extension restore sagittal mobility restricted by suboccipital guarding. Eight slow repetitions. JME 2 Cervical retraction reinforces a neutral head position that reduces the postural strain feeding sensory symptoms. Ten repetitions per set. JME 150 Thoracic rotation restores mid-back motion needed for full diaphragmatic breathing and relaxed upright posture. Eight repetitions per direction. JME 227 Overhead reach opens the thoracic spine and rib cage, supporting the deep breathing that calms an overloaded nervous system. Ten repetitions with controlled tempo. Start your 3-day free trial for joint-specific mobility programming that supports the nervous system regulation behind sensory recovery after concussion. Common Mistakes Assuming the problem is taste rather than smell blunting flavor Neglecting smoke and gas detectors while smell is absent Delaying smell training, which works best started earlier Expecting rapid recovery from a slow, months-to-years process Overlooking reduced appetite and nutrition when food loses appeal Progression Formal smell testing confirms and quantifies the loss and distinguishes it from nasal causes. Smell training, started early and continued over months, aids recovery in some people, while safety adjustments protect against undetected hazards throughout. Recovery follows a slow, months-to-years timeline and ranges from full return to permanent loss depending on the initial damage. Why did I lose my sense of smell after a concussion? The olfactory nerve fibers pass from the nose through tiny holes in a thin plate of bone at the skull base, and the shearing forces of head trauma tear them there, cutting the connection between the smell receptors and the brain. This can happen even without a skull fracture because the damage is where the nerve threads through bone. Will my sense of smell come back after a concussion? It may. The olfactory system can regenerate, so some people recover over months to a few years, some partially, and some permanently lose smell. Recovery is slow, incomplete, and unpredictable, and the degree of initial damage largely determines the outcome. Smell training can improve the odds in appropriate cases. Why does food taste bland if I only lost my smell? Most of what we experience as flavor comes from smell, detected as food aromas reach the smell receptors from the back of the mouth. Basic taste, sweet, salty, sour, bitter, and savory, remains intact, but without smell the rich flavor is lost, so food seems bland or flavorless even though taste itself works. What is smell training and does it work? Smell training involves deliberately smelling a set of distinct scents, such as rose, lemon, clove, and eucalyptus, twice daily over months to stimulate the regenerating olfactory system. It can aid recovery in some people, works best started early, and requires consistency over a prolonged period. Not everyone recovers, but it improves the odds. What safety precautions do I need with anosmia? Because smell warns of hazards, install and maintain smoke and gas detectors, be careful with food expiration and cooking, and use electric rather than gas appliances where possible. These protect against fire, gas leaks, and spoiled food that you can no longer detect by smell while it is absent. Why Sensory Symptoms Happen After Concussion Sensory symptoms after concussion arise from disrupted sensory processing rather than damage to the sense organs alone. Concussion strains the connections between brain regions, alters the balance of excitation and inhibition, and leaves the nervous system in a sensitized, hyperexcitable state (Silverberg et al., 2020). In this state the brain turns up the gain on incoming signals, so ordinary light, sound, smell, taste, and touch are amplified, distorted, or perceived when absent. Some symptoms also reflect direct injury to sensory nerves. Most sensory symptoms improve over weeks to months as the brain recovers and the gain settles, and structured management speeds the process. Graded Exposure and Avoiding Overprotection A common trap in sensory recovery is total avoidance. Completely shielding from light, sound, or activity feels protective, but sustained avoidance makes the nervous system more sensitive over time, narrowing tolerance further. The better approach is graded exposure: staying within a tolerable range while gradually and deliberately increasing exposure as tolerance grows, never pushing far past the point where symptoms flare. This retrains the nervous system to accept normal sensory input. Extreme protection, such as constant dark glasses indoors or continuous earplug use, tends to worsen sensitivity and is used sparingly and strategically rather than continuously. Managing Sensory Overload Reduce competing sensory input by handling one channel at a time Take planned breaks in a calm, low-stimulation environment before overload builds Use diaphragmatic breathing to lower the arousal that amplifies sensitivity Pace demanding sensory environments rather than avoiding them entirely Protect sleep, since fatigue lowers sensory tolerance Treat coexisting headache, since pain and sensory sensitivity feed each other When to Seek Specialist Assessment Persistent or worsening sensory symptoms, symptoms that interfere with work or daily life, and any symptom with concerning features warrant specialist assessment. Hearing and sound symptoms are evaluated by an audiologist or ENT, who can test hearing and guide sound therapy. Visual and eye symptoms are evaluated by a neuro-optometrist or ophthalmologist. Smell and taste symptoms are evaluated by an ENT. A physician or neurologist coordinates care and excludes other causes. Pulsatile tinnitus, sudden vision or hearing loss, and rapidly worsening symptoms need prompt evaluation rather than watchful waiting. The Autonomic and Cervical Contribution Sensory symptoms rarely stand alone after concussion. Autonomic dysregulation keeps the nervous system in a heightened, sympathetic-dominant state that amplifies sensitivity, and cervical dysfunction feeds headache, dizziness, and sensory strain through shared brainstem pathways. Regulating the autonomic nervous system with diaphragmatic breathing and graded activity, and addressing the neck with mobility and manual therapy, lower the background arousal on which sensory symptoms ride. This is why calming the nervous system as a whole often eases sensory symptoms that specialist treatment alone does not fully resolve. References Proskynitopoulos, P. J., Stippler, M., & Kasper, E. M. (2016). Post-traumatic anosmia in patients with mild traumatic brain injury (mTBI): A systematic and illustrated review. Surgical Neurology International, 7(Suppl 15), S263-S275. PubMed Patricios, J. S., et al. (2023). Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport, Amsterdam, October 2022. British Journal of Sports Medicine, 57(11), 695-711. PubMed Silverberg, N. D., et al. (2020). Management of concussion and mild traumatic brain injury: a synthesis of practice guidelines. Archives of Physical Medicine and Rehabilitation, 101(2), 382-393. PubMed