I am nearly 20 years older than you, and have been 'dealing' with ugly bruises for years. I can offer a little advice. Understandably, the comments above relate to your question: what can I do about blood bruises on my arms? The best advice I can give: become much more attentive to what you do with your arms. In other words, do you utmost to avoid bruising and tearing your aging skin. Welcome to the geriatric crowd!