1.1. Outline the main causes of sensory loss

This guide will help you answer 1.1. Outline the main causes of sensory loss.

Sensory loss occurs when one or more of the senses – sight, hearing, touch, taste, or smell – becomes impaired or lost. This can impact individuals’ ability to interact fully with their surroundings or communicate effectively. Understanding the main causes of sensory loss helps support workers provide appropriate care to improve quality of life. Below, each major cause of sensory loss is outlined clearly.

What is Sensory Loss?

Sensory loss can affect one sense (single sensory impairment) or more senses at the same time (dual sensory impairment). It can happen suddenly or gradually, depending on the cause.

The most common types of sensory loss are:

• Hearing loss (partial or complete loss of hearing ability)
• Vision loss (partial or complete loss of sight)
• Loss of touch sensitivity (difficulty feeling physical sensations)
• Impaired smell or taste

The causes of sensory loss differ depending on the individual and the sense affected but generally fall into categories such as age-related changes, medical conditions, infections, injuries, or environmental factors.

Age-Related Causes

Age is the leading cause of sensory loss. As people get older, their sensory functions naturally decline.

• Hearing Loss (Presbycusis): Most people over the age of 65 experience some degree of hearing loss. The inner ear’s cochlea and auditory nerves deteriorate over time, making it harder to hear high-pitched sounds or follow conversations.
• Vision Loss: Age-related vision problems such as cataracts (clouding of the lens), glaucoma (pressure damage to optic nerves), and age-related macular degeneration (damage to the central retina) are major causes of vision impairment or blindness in older adults.
• Loss of Touch (Reduced Sensitivity): Ageing can reduce nerve sensitivity, making it harder to sense temperature, pressure, or pain.
• Changes in Smell and Taste: Reduced sensitivity in smell and taste occurs naturally with age because the nerves and receptors responsible for these senses degenerate.

Medical Conditions and Diseases

Certain health conditions affect sensory reliance and contribute significantly to impairments.

• Diabetes: High blood sugar levels damage blood vessels and nerves, leading to problems like retinopathy (vision loss) or neuropathy (loss of feeling in the hands and feet).
• Stroke: A stroke interrupts blood supply to the brain. This can damage regions responsible for sensory processing, leading to visual loss or difficulty sensing touch on one side of the body.
• Meningitis: This infection inflames protective layers around the brain and spinal cord. Survivors may develop hearing loss or multiple sensory impairments.
• Multiple Sclerosis (MS): MS is a neurological condition that disrupts signals between the brain and other parts of the body. It can lead to vision problems, loss of balance, or reduced touch sensitivity.
• Arthritis: Joint inflammation often comes with reduced dexterity and difficulty sensing touch or pressure.
• Dementia: Conditions like Alzheimer’s affect how the brain processes sensory information. Individuals may appear to lose awareness of their surroundings even though the sensory organs are functional.

Congenital Causes

Some individuals are born with sensory impairments caused by genetic conditions or developmental issues during pregnancy.

• Congenital Deafness: This is a form of hearing loss present from birth, often linked to genetic factors, infections in the mother during pregnancy (e.g., rubella), or complications during childbirth.
• Congenital Blindness: Blindness or partial sight loss can result from inherited conditions like retinitis pigmentosa or eye development disorders during pregnancy.
• Sensory Processing Disorders: These occur when the brain has trouble receiving and responding to sensory information. It is particularly noticeable in children with autism.

Injuries and Trauma

Physical injuries or accidents sometimes damage sensory organs or areas of the brain responsible for sensory processing.

• Head Injury: A traumatic brain injury can severely affect hearing, vision, or touch if the parts of the brain controlling these senses are damaged.
• Eye Injuries: Physical trauma to the eyes may lead to temporary or permanent vision loss.
• Ear Trauma: Sudden loud sounds, such as explosions, or direct damage to the ear can cause sudden hearing loss.
• Spinal Cord Injuries: Nerve damage caused by spinal cord injuries can impair the ability to feel or move parts of the body below the injury site.
• Burns: Severe burns on the hands or other parts of the body can destroy nerve endings, reducing the sense of touch.

Infections

Infections are another significant cause of sensory loss, as they can directly or indirectly damage sensory organs.

• Otitis Media (Middle Ear Infection): Chronic infections in the ear can cause hearing loss, especially in children.
• Cytomegalovirus (CMV): This virus can cause hearing loss when contracted, particularly during pregnancy.
• Influenza or Severe Colds: These can temporarily affect taste or smell abilities by irritating the nasal passage.
• Eye Infections: Infections like conjunctivitis (pink eye) or keratitis can result in vision impairment if untreated.
• Meningitis and Encephalitis: Both can cause permanent hearing or vision loss, as well as other neurological effects.

Environmental Factors

Environmental conditions often contribute heavily to both temporary and permanent sensory impairments.

• Noise Pollution: Long-term exposure to loud noises, such as at concerts or in workplaces with heavy machinery, can cause permanent hearing damage.
• Sunlight Exposure: Prolonged exposure to ultraviolet (UV) light without eye protection increases the risk of macular degeneration and cataracts.
• Chemical Exposure: Chemical burns or prolonged contact with certain substances can impair eyesight or sensitivity in exposed areas, such as the skin.
• Pollution: Poor air quality irritates the nasal pathways, making taste and smell less sharp.

Lifestyle Choices and Behaviours

Certain behaviours and decisions can increase the risk of sensory impairment.

• Smoking: Chemicals in cigarettes impair blood flow and damage sensory receptors, particularly those responsible for taste and smell.
• Excessive Alcohol Use: Alcohol abuse can lead to neuropathy, affecting the sense of touch and balance.
• Unsafe Work Practices: Failure to use protection in noisy or hazardous environments contributes to hearing and vision loss respectively.
• Poor Diet: A diet lacking essential vitamins (like Vitamin A) impacts vision health and overall sensory function.

Genetic Factors

Heredity plays a major role when it comes to certain types of sensory loss.

• Inherited Conditions: Diseases like Usher syndrome involve both hearing and vision loss.
• Family History of Sensory Loss: People with relatives who have sensory impairments may inherit the condition or a predisposition to it.

Temporary Sensory Loss

Sensory loss doesn’t always have a permanent cause; temporary impairments occur under certain conditions.

• Blocked Ears (Hearing): Wax build-up or a foreign object in the ear canal can temporarily reduce hearing.
• Eye Fatigue: Extended use of screens or lack of sleep may lead to temporary blurry vision.
• Blocked Nose (Smell and Taste): Colds or sinus infections temporarily block the nasal passage, reducing the sense of smell and taste.

Improving Awareness as a Support Worker

When working with individuals, recognise that sensory loss is not just a medical issue but can also be social and emotional. Losing senses, even temporarily, can make people feel isolated or frustrated. Identifying the possible causes and tailoring care to their needs allows you to support them in maintaining independence and confidence in daily life.