Kennedy's condition is called spasmodic dysphonia, which is a neurologic disorder that can affect the voice and speech by causing the muscles that generate a person’s voice to go into periods of spasm, according to Penn Medicine. It is a lifelong condition, but can be improved with treatment in some cases, according to Penn Medicine.

Robert F. Kennedy Jr., a former presidential candidate and environmental activist, endorsed Donald Trump last year and threw his weight behind a campaign to “Make America Healthy Again.” For the past two decades he has been best known for airing skeptical views on vaccines.

If approved, Kennedy will control a $1.7 trillion agency that oversees food and hospital inspections, hundreds of health clinics, vaccine recommendations and health insurance for roughly half the country.

Spasmodic dysphonia (SD), sometimes referred to as laryngeal dystonia, is a rare neurological condition impacting the voice and speech that impacts approximately 50,000 people in North America. For people with SD, muscles spasms in the larynx (also known as the voice box) cause the voice to sound tight, strangled or strained.

The hearing, which began at 10 a.m., will examine the worthiness of RFK Jr. to be Secretary of Health and Human Services. Watch the RFK Jr. confirmation hearing live on C-SPAN (Optimum channel 80, Spectrum channel 49).

Robert F. Kennedy Jr. was confronted with a number of his baseless claims and a vexing abortion issue. But Republican senators treaded lightly.

Democrats focused on Kennedy's anti-vaccine advocacy. Republicans probed the former Democratic leader on his abortion and agriculture views.