Mayo Clinic also notes that inappropriate crying, laughing, or yawning may occur in ALS. ([Mayo Clinic][1])
These changes result from neurological effects rather than simply being an emotional reaction to the diagnosis.
## Does ALS Cause Numbness or Loss of Sensation?
Usually, ALS primarily affects **motor neurons**, which control movement.
Sensation such as touch, smell, hearing, and taste is generally preserved. Mayo Clinic notes that ALS usually does not affect bladder function or the senses. ([Mayo Clinic][1])
That distinction can help doctors differentiate ALS from conditions that primarily affect sensory nerves.
However, symptoms should never be interpreted in isolation.
## Does ALS Cause Pain?
Pain is generally not one of the characteristic early symptoms of ALS.
Mayo Clinic notes that pain is usually absent early in the condition. ([Mayo Clinic][1])
Pain can develop later because of muscle stiffness, immobility, joint strain, or other complications, but unexplained pain alone is not a typical early warning sign.
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## What Causes ALS?
For most people, the exact cause is unknown.
Approximately **90% of ALS cases are sporadic**, meaning there is no obvious family history. Around 10% are familial and linked to inherited genetic variants. ([NINDS][3])
Scientists have identified multiple genes associated with ALS, including:
* C9orf72
* SOD1
* FUS
* TARDBP
Research continues into how genetics, cellular processes, and environmental factors contribute to the disease.
## How Is ALS Diagnosed?
There is no single simple blood test that confirms ALS.
Diagnosis generally involves:
* Detailed neurological examination
* Medical history
* Electromyography (EMG)
* Nerve-conduction studies
* Blood tests
* Imaging when appropriate
* Other testing to exclude similar conditions
ALS can be difficult to diagnose early because several neurological and muscular diseases can mimic its symptoms. ([Mayo Clinic][2])
## Conditions That Can Mimic ALS
Progressive weakness, twitching, or speech problems can occur with many conditions other than ALS.
Doctors may consider possibilities such as:
* Peripheral neuropathy
* Cervical spine problems
* Myasthenia gravis
* Multiple sclerosis
* Vitamin deficiencies
* Thyroid disorders
* Certain muscular diseases
* Other motor-neuron disorders
This is why searching symptoms online cannot provide a reliable diagnosis.
## When Should You See a Doctor?
Arrange medical evaluation if you develop **progressive and unexplained** symptoms such as:
