Symptoms and Triggers of Orthostatic Tremor

For many people with Primary Orthostatic Tremor (POT), the most difficult part of the condition is describing a sensation that others cannot see. While the tremor typically happens at a very high frequency (13–18 times per second), the movements are often too small for the naked eye to detect ^[1]. This page explains the specific sensations, triggers, and physical habits that define life with POT.

The Sensation of “Shaky Legs”

The primary symptom of POT is not necessarily a visible shake, but a profound sense of unsteadiness and an “internal” vibration ^[2]. Patients frequently describe this feeling as:

• Internal Trembling: A sensation of buzzing, rapid vibrating, or electricity running through the legs ^[1].
• Fear of Falling: An overwhelming feeling that your legs might “give out,” even if you have never actually fallen ^[3].
• Bilateral Shakiness: The sensation often affects both legs equally at the same time, though individual variation exists ^[4].

Because these feelings are invisible, POT is often called an “invisible disability.” You may look perfectly still to a bystander while feeling as though your legs are violently vibrating on the inside ^[3].

What Triggers the Tremor?

The “on-switch” for POT is weight-bearing. The symptoms are most intense during:

• Quiet Standing: Standing still (such as in a checkout line or at a sink) is the primary trigger. The longer you stand, the more intense the vibration and unsteadiness become ^[5].
• Slow Walking: Walking slowly can sometimes be harder than walking quickly, as it requires more time spent balancing on one leg at a time ^[6].
• Dual-Tasking: Performing a second task while standing—such as carrying a heavy bag, talking on the phone, or trying to solve a mental problem—can significantly worsen your sense of balance ^[6].
• Reduced Vision: Many patients find that their instability worsens if they close their eyes or walk in the dark, as they can no longer use visual cues to help their brain compensate for the leg vibration ^[6]. Never close your eyes to test your balance at home, as this carries a high risk of falling. Balance testing should only be done under the supervision of a clinician.

How the Body Tries to Compensate

Over time, many people with POT move their bodies in specific ways to try to gain a sense of stability. These are known as compensatory postures, and you might find yourself doing them without even realizing it. Note that these are variable signs, not definitive features:

• Broad-Based Stance: Spreading your feet wider apart than usual to create a more stable base ^[2].
• Bent Knees: Keeping the knees slightly flexed rather than locked ^[2].
• Abnormal Tandem Gait: Difficulty walking “heel-to-toe” in a straight line, as this forces you to balance on a narrow base ^[2].

How to Find Immediate Relief

The “off-switch” for the tremor is just as predictable as the trigger. Symptoms almost always disappear or significantly improve when you:

• Sit or Lie Down: Relieving the weight from your legs usually stops the tremor immediately ^[4].
• Walk Quickly: Increasing your pace can often “override” the tremor rhythm, making you feel more stable ^[6]. However, always prioritize your safety over speed. Do not rush if you feel unbalanced.
• Lean or Support Your Weight: Transferring your weight to your arms—by leaning on a sturdy countertop or using a properly fitted rolling walker—provides instant relief ^[7]. Be cautious: do not rely on unstable items like shopping carts or lightweight chairs that can tip or roll away.

Symptoms Beyond the Legs

While POT primarily targets the legs, some patients may experience related symptoms in other parts of the body. In some “cohorts” (groups of patients), doctors have observed upper limb tremors (shaking in the hands) or mild parkinsonian signs, such as a slight slowness of movement or reduced arm swing ^[2][8]. If you notice these symptoms, it is important to mention them to your doctor, as they help distinguish between “isolated” POT and “OT-plus” ^[9]. Individuals with POT may also experience higher levels of anxiety or depression, often stemming from the social isolation caused by the difficulty of standing in public spaces ^[2].