What is Raynaud’s phenomenon? Raynaud’s phenomenon is a condition that affects your blood vessels. If you have Raynaud’s phenomenon, you have periods of time called “attacks” when your body does not send enough blood to the hands and feet. Attacks usually happen when you are cold or feeling stressed. During an attack, your fingers and toes may feel very cold or numb. Raynaud’s phenomenon is also called Raynaud’s disease or Raynaud’s syndrome.
What is pachyonychia congenita? Pachyonychia congenita is a very rare disorder. It causes thick nails and painful calluses on the bottoms of the feet. In some cases, blisters also form on the palms of the hands.