Symptoms, Progression, and Emergencies in ALS

Living with ALS means learning to navigate a landscape of physical changes that can feel unpredictable. While every person’s journey with the disease is unique, the symptoms follow patterns based on which nerves are affected and where the weakness begins. Understanding these patterns—and knowing how to distinguish a routine change from a medical emergency—is a vital part of managing your care.

How ALS Begins: Two Main Paths

ALS is categorized by where the first symptoms appear. This “site of onset” helps your care team anticipate which challenges might arise first.

• Spinal (Limb) Onset: About 70% of people experience symptoms first in their arms or legs ^[1]. This might feel like “dropped foot” (tripping over your toes), difficulty with fine tasks like buttoning a shirt, or unexpected weakness when lifting objects ^[2].
• Bulbar Onset: In about 25% of cases, the first signs affect the muscles used for speaking, swallowing, and breathing ^[1]. You may notice slurred speech (dysarthria), a change in your voice’s pitch, or frequent coughing when drinking liquids ^[3]. Bulbar-onset ALS tends to progress more quickly than spinal-onset ALS ^[4].

The Two Types of Nerve Signs

ALS affects two different sets of motor neurons, and most people will eventually show signs of both:

1. Upper Motor Neurons (UMN): These nerves run from your brain to your spinal cord. When they are affected, you may experience spasticity (muscle stiffness), unusually brisk reflexes, or clonus (rhythmic muscle contractions) ^[5][6].
2. Lower Motor Neurons (LMN): These nerves run from your spinal cord to your muscles. Damage here causes muscle atrophy (wasting), significant weakness, and fasciculations (small, involuntary muscle twitches that look like “flickering” under the skin) ^[2][6].

Other Common Symptoms

ALS is not just about limb and bulbar weakness. You may also experience fatigue, muscle cramps, excess saliva (sialorrhea) due to weakened swallowing muscles, cognitive or behavioral changes, or Pseudobulbar Affect (PBA)—uncontrollable episodes of laughing or crying that don’t match how you actually feel. These are discussable ALS symptoms, not personal failures, and many can be treated.

Recognizing Respiratory Changes (When to Call the Clinic)

Because ALS affects the muscles that help you breathe, respiratory function is monitored closely. Often, the first signs of breathing weakness happen at night—a condition called nocturnal hypoventilation ^[7].

You should contact your ALS clinic for an urgent same-day or next-day evaluation if you notice:

• Morning headaches or feeling unrefreshed after a full night’s sleep ^[8].
• Orthopnea: Needing to prop yourself up on several pillows to breathe comfortably while lying flat ^[9].
• Frequent night waking or feeling short of breath while resting ^[9].
• Excessive daytime sleepiness or new difficulty concentrating ^[8].
• Note: Normal oxygen saturation on a home pulse oximeter does NOT mean your breathing is fine. ALS often causes carbon dioxide buildup before oxygen levels drop.

When to Call 911: ALS Emergencies

Most changes in ALS happen gradually over weeks or months. However, two specific situations require immediate emergency medical intervention.

1. Acute Respiratory Distress (Breathing Failure)
Call emergency services immediately if you or your loved one experiences:

• Inability to speak more than one or two words between breaths.
• The skin “sucking in” around the neck or ribs during breathing.
• Blue, gray, or pale tint to the lips, fingernails, or skin.
• Sudden confusion, extreme agitation, or loss of consciousness ^[10].

2. Acute Choking or Aspiration Crisis
While frequent coughing during meals is a sign to call your clinic, a total airway obstruction or a severe choking episode requires immediate help.

• Call 911 immediately if an object or food is completely blocking the airway. Begin standard choking first aid (such as abdominal thrusts/the Heimlich maneuver) as directed by the dispatcher ^[11].
• CRITICAL WARNING: Do NOT use a mechanical cough-assist device or suction machine to try to remove a solid food obstruction. These devices are for clearing liquid secretions and mucus, not solid objects, and using them improperly can delay lifesaving first aid. They should only be used during an emergency if your respiratory team has given you a specific, written plan for that situation ^[12].

Patterns of Progression

ALS typically “spreads” from its starting point to nearby muscle groups ^[13]. While the speed of this spread varies greatly between individuals and does not follow a strict rule, your medical team will use regular measurements—like Forced Vital Capacity (FVC) and other objective measures—to stay ahead of these changes ^[14].

Maintaining a close relationship with a multidisciplinary clinic ensures that as your symptoms evolve, your support system—from speech-language pathologists to respiratory therapists—is already in place ^[15].