It's sometimes a behavior to get attention, or it could be that she is concerned and wants to be close to you. She likely does not understand that standing on you his hurting you. Dogs don't understand how fragile humans are!
Whatever her reason, you should train an alternative behavior that is incompatible with standing on you. For example, instead of standing on you, train her to lay at your feet, or if you're laying on the couch or bed, train her to lay on the floor beside you.
Use small treats to lure her into position. You might want to start this training by pretending to be sick or having an episode, because I"m sure the last thing you want to be doing while you are feeling unwell is training a dog to not stand on you. When your dog sees the specific behaviors that indicates you are unwell, she will default to her training.
You may consider contacting a positive reinforcement trainer, perhaps one that is familiar with therapy dog training or training dogs to help with medical issues, to help you figure out how to train your dog to react appropriately when you are feeling ill.
Whatever her reason, you should train an alternative behavior that is incompatible with standing on you. For example, instead of standing on you, train her to lay at your feet, or if you're laying on the couch or bed, train her to lay on the floor beside you.
Use small treats to lure her into position. You might want to start this training by pretending to be sick or having an episode, because I"m sure the last thing you want to be doing while you are feeling unwell is training a dog to not stand on you. When your dog sees the specific behaviors that indicates you are unwell, she will default to her training.
You may consider contacting a positive reinforcement trainer, perhaps one that is familiar with therapy dog training or training dogs to help with medical issues, to help you figure out how to train your dog to react appropriately when you are feeling ill.