Thank you for your inquiry regarding the safety of laser procedures on the upper arms, especially after the removal of 21 lymph nodes due to breast cancer. Generally, you can safely undergo laser treatments on the upper arms. However, the specific type of laser procedure is crucial in assessing the associated risks. Whether you're considering external lasers for skin tightening, hair removal, or addressing vascular lesions, or you're thinking about J-plasma, which employs subdermal radio frequency, each method has its unique considerations. Lasers can often be used on the upper arms without major concerns after lymph node removal. Nevertheless, always consult with your healthcare provider and a laser specialist to determine the best approach for your specific circumstances. Wishing you the best in your decision-making process. Sincerely, Dr. Katzen