The correct answer to this open question is the following.
The ways that I think the life of a miner would have been difficult are the following.
First, we had to specify that although you did not mention it, we are talking about the time of the westward expansion in California during the Gold Rush.
Once said that I think that the miners in that time lived under very difficult conditions. The place was only land, a wilderness place. No infrastructure, no homes, no services. Miners worked with basic tools such as shovels. Miners worked hard since early in the morning but they really never found any significant gold at all.